Nourkrin® Review: Can Proteoglycans Actually Reverse Hair Loss?

Article Summary

Nourkrin® markets its supplements as a “natural approach to hair loss”. The company differentiates itself with Marilex®: a “bioactive proteoglycan formula”. Three human studies suggest Nourkrin® products are effective at regrowing hair. Upon further investigation, each study has significant flaws that make it hard to discern the product’s true effects. Some studies lacked placebo groups; others did not specify the hair loss types of participants; others only assessed subjective (rather than objective) hair parameters. Even still, Nourkrin® might have some effect. This article analyzes the the studies, the ingredients inside Nourkrin®, and provides a basis for who might be a good candidate for Nourkrin®.

Full Article

Nourkrin® with Marilex® is a hair supplement marketed by Nourkrin®. The company claims this is “a clinically proven Proteoglycan Replacement Therapy formulated to stop hair loss, promote hair growth and maintain a normal healthy Hair Growth Cycle in women and men, in contrast to conventional therapies”.^[1]Nourkrin®, (no date), How does Nourkrin® work? Available at: https://nourkrin.co.uk/the-hair-growth-cycle/ (Accessed: 26 January 2023 Nourkrin® has been around for 30 years and says that it “is recognized by scientists, doctors, dermatologists and trichologists worldwide – making Nourkrin® the uncontested marker lead in its category globally “.^[2]Nourkrin, (no date), Tried and Tested.  Available at: https://nourkrin.co.uk/scientifically-proven/ (Accessed: 26 January 2023

In this company review, we’ll dive into the science behind proteoglycans and explain how Nourkrin® with Marilex® might work., We will evaluate claims made by the company and compare the available clinical data to help you determine whether you think this is a product worth using.

Key Takeaways

• Branding. Nourkrin® with Marilex® is an oral supplement that markets itself as a ‘natural’ approach to hair loss, with Nourkin stating that it is “completely drug-free, based on natural ingredients, completely safe”.^[3]Nourkrin (no date), What is Nourkrin? Available at: https://nourkrin.com/questions-answers/ (Accessed: 26 January 2023 The company has products available for both men and women. However, their before-and-after photos have more women (5-1 vs. men) and two female-only studies with only women, and one mixed study (admittedly heavily skewed towards men).
• Differentiation. Nourkrin® with Marilex® differs from other products as Nourkrin® claims it is “the only Proteoglycan Replacement Therapy on the market”.^[4]Nourkrin®, (no date), About Nourkrin® with Marilex®. Available at: https://nourkrin.com/questions-answers/ (Accessed: 26 January 2023 They also state that “Marilex® is a proprietary ingredient, for which they hold exclusive intellectual property rights, thus setting  Nourkrin® apart from other products claiming to contain similar ingredients.^[5]Nourkrin®, (no date), Is Nourkrin® the only product worldwide containing Marilex®? Available at: https://nourkrin.com/questions-answers/ (Accessed: 26 January 2023
• Clinical Support. Three studies have been published looking at the use of Nourkrin® with Marilex®. We have summarized them below:
  • The first study was a randomized, placebo-controlled study for the first 6 months, and then an open-label study for the remainder of the study duration (a further 6 months for the treated group and 12 months for the former placebo group). The study included 51 men and 4 women with unspecified hair loss.^[6]Thom, E. (2006). Nourkrin: Objective and subjective effects and tolerability in persons with hair loss. Journal of International Medical Research, 34(5), 514-519. Available at: … Continue reading In the first 6 months, the treated group showed a 35.7% increase in hair number compared to the placebo group’s 1.5% increase in hair number (though the method for measuring was not disclosed). For the rest of the study, patient satisfaction was the only measured metric (via questionnaires). At the 12-month mark, the treated group showed an average score of 8.1/10 in satisfaction. After 12 months of the former placebo group being treated with Nourkrin®, they showed a satisfaction score of 7.9/10. 
  • The second study was an open-label (meaning the participants knew what they were receiving) consumer perception study of 114 women (aged between 18-64) that had either been diagnosed with androgenetic alopecia or telogen effluvium.^[7]Wadstein, J., Thom, E. (2019). Treating Diffuse Hair Loss using Nourkrin® Woman (with Marilex) – An Open -Label, Subjective, Outcome Study on Hair Growth and Appearance, Self Confidence and … Continue reading After 6 months of taking Nourkrin® with Marilex®, the researchers found that: 96.49% of patients reported improvement in hair growth; 97.37% of patients reported improvement in their hair appearance and quality; 80.70% of patients had more satisfaction and confidence in their hair; 98.25% of patients felt satisfied with Nourkrin® treatment.
  • The third study was also an open-label consumer perception study, this time including 67 women that had either androgenetic alopecia or telogen effluvium, and were aged between 18-64.^[8]Mattos, S.M, Thom, E., Wadstein, J. (2020). Nourkrin® Woman with Marilex® Enhances Hair Growth and Appearance and Improves Hair Confidence in Women with Diffuse Hair Loss from Brazil: An … Continue reading  The researchers found that: 94.03% of participants reported improvement in hair growth; 92.54% of patients reported improvement in hair appearance and quality; 83.58% of patients had more satisfaction and confidence in their hair; 97.01% of patients felt satisfied with Nourkrin® with Marillex® treatment.
• Concerns.
  • While the results of the first study seem positive at first glance, there are several issues, such as: not knowing the type of hair loss of the participants; not knowing how the number of hairs was counted (or by whom); the fact that the study is heavily skewed towards men, with only 4 women involved in the study.
  • The two following studies included people who had telogen effluvium, which is a type of hair loss that can self-resolve (i.e., clear up by itself, without treatment). If this spontaneously occurs during the treatment period, this hair recovery could be falsely attributed to the action of the supplement.
  • Furthermore, there were no placebo-controlled groups in two of the studies, and thus investigators relied entirely on subjective satisfaction scores instead of objective quantitative approaches, such as counting hair or measuring hair thickness.
  • The patient satisfaction questionnaires were composed of questions that required ‘yes’ or ‘no’ answers which, while they are simpler to use, force the participant to choose an absolute answer when, in reality, the patient may not have experienced a dramatic effect. For these reasons, most hair loss studies have standardized self-assessment surveys that use 5- or 7-point scales to denote perceived hair changes. These are believed to give fairer assessments of a therapy’s true perceived effect, while ‘yes’ / ‘no’ surveys are more often used for consumer surveys to generate data that can be used as selling points for a product line.
• Recommendations to Nourkrin®. Nourkrin® could provide its prospective buyers with more reliable clinical data by funding larger-scale, pre-registered trials that use objective measurements of hair growth, thickness, and number as the main readout as outcomes. The studies should also include data on both men and women. Furthermore, Nourkrin® could ensure that they provide sufficient details about the participant, such as the types of hair loss the patients had, so the consumer can ensure that the product will work for them.
• Our Current Thoughts. We cannot currently recommend this product until clear clinical data backs up the product to show that it works. If Nourkrin® can back up its claims with objective data, then we would be happy to review it again. In the interim, people who are not cost-sensitive might consider Nourkrin®, albeit as an adjuvant to better-supported hair loss treatments.

What is Nourkrin®?

Nourkrin® is a brand owned by a company called Pharma Medico Group, which also owns Nourella®, a brand with a range of products targeted towards skin aging, and Zymbilan®, a brand with products targeted towards people with dermatitis, eczema, and psoriasis.^[9]Pharma Medico, (no date), The Science of Natural Well-Being. Available at: https://pharmamedico.com/ (Accessed: 23 January 2023

Nourkrin® produces hair care products that range from oral supplements to shampoos and conditioners. Their flagship product is called Nourkrin® with Marilex® (for women or for men), which they state, “is the result of more than 100 scientific studies and clinical papers as well as several user studies published in leading peer-reviewed clinical journals over the last 30 years”.^[10]What is Nourkrin, (no date), Question and Answer. Available at: https://nourkrin.co.uk/question-and-answers/ (Accessed: 23 January 2023

There are two products under this name, one for women and one for men. The product branded for women contains 600mg of the Marilex® formula, whilst the one for men contains 720mg. No reason is given for the difference in quantities.^[11]Nourkrin®, (no date), Nourkrin® Woman. Available at: https://nourkrin.co.uk/product-category/nourkrin-woman/ (Accessed: 26 January 2023 ^[12] Nourkrin®, (no date), Nourkrin® Man. Available at: https://nourkrin.co.uk/product-category/nourkrin-man/ (Accessed: 26 January 2023

Throughout the website, Nourkrin® is very clearly trying to present itself as a risk-free and natural approach to hair loss, even stating that “Nourkrin® is completely safe as it is 100% drug-free”.^[14]Nourkrin®, (no date), Is Nourkrin safe to use? Available at: https://nourkrin.co.uk/question-and-answers/ (Accessed: 23 January 2023

A lot of companies such as this one, use marketing terms such as “drug-free”. However this really doesn’t mean anything. The definition of a drug is “any substance (other than food) that is used to prevent, treat, or relieve symptoms of a disease or abnormal condition”.^[15]NCI, (no date), drug. Available at: https://www.cancer.gov/publications/dictionaries/cancer-terms/def/drug (Accessed: 23 January 2023 Because it’s a food supplement, these are not classed as drugs, however, stating that your product is safe because it’s drug-free is basically nonsense. There are plenty of “drug-free” supplements that may cause health problems to those taking them. Examples include fish oil supplements, vitamin E, selenium, beta-carotene, & antioxidants.

Food supplements are also not required to be safety-tested by the FDA before they go on the market, so risk-free claims must come through rigorous published testing and registered trials.^[16]FDA, (2022), Questions and Answers on Dietary Supplements. Available at: https://www.fda.gov/food/information-consumers-using-dietary-supplements/questions-and-answers-dietary-supplements (Accessed: … Continue reading

Who is their target consumer?

Nourkrin® with Marilex supplements are marketed towards men and women (as mentioned, they have separate products specifically for men and women). However, the case studies that are presented on their website are mostly from female cases (5 women and 1 man).^[17]Nourkrin, (no date), Case Studies. Available at: https://nourkrin.com/case-studies/ (Accessed 23 January 2023

What Nourkrin® products are offered?

There are 3 products marketed under the Nourkrin® brand, sold in different size packs, plus a range of shampoos and conditioners designed to maintain overall hair quality.

Product	Contains Marilex?	Size	Price
Nourkrin® Man	Yes	60 tablets 180 tablets 360 tablets	1 month – $62.98 3 months – $123.56 6 months – $222.51
Nourkrin® Woman	Yes	30 tablets 60 tablets 180 tablets 360 tablets	15 days – $35.79 1 month – $62.98 3 months – $123.56 6 months – $222.51
Nourkrin® Maintain	Yes	30 tablets 90 tablets 180 tablets	1 month – $37.02 3 months – $86.47 6 months – $222.51
Nourkrin® Conditioner	No	150ml	$37.02
Nourkrin® Scalp Serum	No	30ml	$30.84
Nourkrin® Shampoo	No	150ml	$16.01
Duo Shampoo and Conditioner	No	150ml each	$28.37
Trio Shampoo, Conditioner and Serum	No	150ml + 150ml + 30ml	$55.57

Table 1 Adapted from:^[18]Nourkrin, (no date), Products. Available at: https://nourkrin.co.uk/products/ (Accessed: 23 January 2023

You can also buy combinations of products (i.e., Nourkrin® Woman 3 months plus shampoo and conditioner for $123.77).^[19]Nourkrin, (no date). Nourkrin Woman. Available at: https://nourkrin.co.uk/product-category/nourkrin-woman/ (Accessed: 23 January 2023

How do they claim Nourkrin is unique?

Nourkrin® states that its product is unique because it’s “the only Proteoglycan Replacement Therapy on the market, and it is scientifically proven to be a drug-free, completely safe and side effect free method of increasing the concentration of specific hair follicle proteoglycans and hereby normalizing the Hair Growth Cycle and supporting normal hair growth”.^[20]Nourkrin®, (no date), Frequently Asked Questions. Available at: https://nourkrin.com/questions-answers/ (Accessed: 23 January 2023

However, it should be noted that it is the only proteoglycan replacement therapy on the market because it’s the only product that calls itself a proteoglycan replacement therapy. Furthermore, many companies offer their products as drug and side-effect-free, so there is not a lot to be said for the legitimacy of their claim.

What is their pricing?

The pricing for each of the products can be seen above (Table 1), however, Nourkrin® states that their “Nourkrin® with Marilex is scientifically developed as a 6-month program”.^[21]Nourkrin®, (no date), Frequently Asked Questions. Available at: https://nourkrin.com/questions-answers/ (Accessed: 23 January 2023 So if you were to follow that program length, it would set you back $222.51 for 6 months of the supplement.

Compared to the price of other supplements like Nutrafol (of which 6 months’ worth will set you back around $474), the price doesn’t seem that bad, relatively speaking.

Let’s have a look then at whether there is any scientific evidence to back up the claims made on Nourkrin’s website. To answer this, we will start by looking at Nourkrin’s key differentiator – a patented ingredient called Marilex®.

Product Science: Deep Dive

Nourkrin® focuses heavily on the issue of “proteoglycan follicular atrophy” and states that “hair loss and hair growth disruptions can be explained by a ‘lower than normal’ concentration of hair growth regulating proteoglycans that causes follicular degradation”.^[22]Nourkrin, (no date), What is Proteoglycan Follicular Atrophy. Available at: https://nourkrin.com/what-are-proteoglycans/ (Accessed: 24 January 2023 We will cover proteoglycans in more detail below.

Nourkrin® mentions proteoglycan follicular atrophy a lot, however, there does not appear to be published literature associated with this term, outside of the Nourkrin® website. So, we will use their definition of it: “Proteoglycan Follicular Atrophy is today a clinically established pathology and a condition where a wasting away of selective proteoglycans from the dermal papilla, the inner and outer root sheath, occurs, coupled with an ever-decreasing ability of the body to reproduce these in a normal, healthy manner”.^[23]Nourkrin, (no date), What are Proteoglycans? Available at: https://nourkrin.co.uk/what-are-proteoglycans/ (Accessed: 24 January 2023

In reality, as we know, hair loss and hair growth disruptions can’t be explained by one specific cause. A multitude of factors can induce hair loss, some of which are still not well identified.

Below, we will discuss what Marilex® is, shed some light on proteoglycans and discuss whether there’s any evidence to suggest that they are implicated in hair loss.

Marilex®

Marilex® is a “fractionated fish extract with specific lectican proteoglycans”.^[25]Nourkrin, (no date), What is Marilex? Available at: https://nourkrin.com/what-are-proteoglycans/ (Accessed 24 January 2023 But what does that mean? Well, most proteoglycans are proteins that have one or more polysaccharide chains (carbohydrate chains) attached, and they can be found in the extracellular matrix (the substance between cells). They play important roles throughout the body including in growth, cell migration, cell adhesion, ordering of collagen fibrils, immune functionality, and in wound healing.^[26]Couchman, J.R., Pataki, C.A. (2012). An Introduction to Proteoglycans and Their Localization. Journal of Histochemistry and Cytochemistry. 60(12), 885-897. Available at: … Continue reading

There are four members of the family of lectican proteoglycans. These are: aggrecan, versican, neurocan and brevican. Aggrecan is mostly found in cartilage, versican in blood vessels, and neurocan and brevican are mostly found within the brain.^[27]Couchman, J.R., Pataki, C.A. (2012). An Introduction to Proteoglycans and Their Localization. Journal of Histochemistry and Cytochemistry. 60(12), 885-897. Available at: … Continue reading.

In regard to the hair follicle, you can also find lectican proteoglycans (amongst other types of proteoglycan that aren’t members of the lectican group). A study was completed to determine proteoglycan expression patterns (locations of expression) within the human hair follicle.^[28]Malgouris, S., Thibaut, S., Bernard, B.A. (2007). Proteoglycan expression patterns in human hair follicle. British Journal of Dermatology. 158, 234-242. Available at: … Continue reading

Versican was shown to be expressed within the dermal papilla (area in the bulb of the hair follicle where specialized cells exist that play a key role in hair follicle cycling) and at the end nearer to the bulb of the connective tissue sheath (a tubular sheath on the outside of the hair follicle that holds it in place within the dermis). Aggrecan is also expressed in the connective tissue sheath, with a particularly high expression at the bottom of the hair follicle (Figure 2).^[29]Malgouris, S., Thibaut, S., Bernard, B.A. (2007). Proteoglycan expression patterns in human hair follicle. British Journal of Dermatology. 158, 234-242. Available at: … Continue reading At the time of writing, there does not appear to be any published data elucidating whether neurocan and brevican are expressed within the hair follicle.

Another study compared the expression of versican in the hair follicles of 10 “old” (donor age 83.8 years) and “young” men (donor age 33.3 years) with no obvious alopecia or scalp issues. They found that expression of versican significantly decreased in the dermal papilla (DPs) of “old” men but stayed the same in the connective tissue sheath (CTS) (Figure 3).^[30]Jo, S.J., Kim, J.Y., Jang, S., Choi, S.J Jo, Seong Jin, M.D, Kim, J. Y., M.D, Jang, S., Choi, S. J., Kim, Kyu Han, M.D., Kwon, Ohsang, (2016). Decrease of versican levels in the follicular dermal … Continue reading

Other studies have also shown that expression of versican decreases in the transitional (catagen) stage (the stage between growing and non-growing parts of the hair cycle) and is barely expressed at all in the non-growing (telogen) stage and evidence to suggest a relationship between versican expression and aggregative DP cell growth further indicating that versican has a role to play in the anagen follicle.^[32]Soma, T., Tajima, M., & Kishimoto, J. (2005). Hair cycle-specific expression of versican in human hair follicles. Journal of Dermatological Science, 39(3), 147-154. Available at: … Continue reading ^[33]Feng, M., Yang, G., & Wu, J. (2011). Versican targeting by RNA interference suppresses aggregative growth of dermal papilla cells. Clinical and Experimental Dermatology, 36(1), 77-84. Available … Continue reading

The aggregative growth of DP cells is important for inducing the formation of hair follicles.^[34]Matsuzaki, T., & Yoshizato, K. (1998). Role of hair papilla cells on induction and regeneration processes of hair follicles. Wound Repair and Regeneration, 6(6), 524-530. Available at: … Continue reading

So, there is some evidence indicating that proteoglycans may be biologically relevant to the human hair follicle. However, there isn’t much evidence showing that changes in proteoglycan expression are linked to hair follicle disorders. Moreover, is there any evidence showing that proteoglycan replacement supplements, such as Nourkrin®, have any beneficial effect?

In other words, the question still remains: does Nourkrin® actually work?

Does Nourkrin® work as a hair loss treatment?

Well, there are no verified reviews for Nourkrin on review websites like Trustpilot (which may be considered strange since the brand has been around for 30 years), and, whilst there are testimonials, we have no way of knowing the type of hair loss the customers were experiencing or how long they were taking the product for.

There are, however, some before-and-after photos from users of the product (5 to be exact), of which there do appear to be some improvements (Figure 4), however, these were of more rare hair loss conditions such as alopecia areata or of conditions that may resolve by themselves, like telogen effluvium (it’s worth noting no patients in any of the conducted trials had alopecia areata). Additionally, the cases of female pattern hair loss seem to show only marginal improvements at best.

As mentioned earlier, there have been three studies completed to date that may give us a clearer idea of whether Nourkrin® actually works. Let’s go over them in greater detail…

Clinical data

Whilst these studies were completed using Nourkrin® with Marilex® tablets supplied by Nourkrin’s parent company Pharma Medico International, it is not clear whether Nourkrin® paid for these studies to be completed.

Study one

It is not clear whether this study was paid for by Nourkrin® however it does mention that the tablets were supplied by Pharma Medico International, the company that owns Nourkrin®.

The first study, completed in 2006, was a randomized, double-blind, placebo-controlled study followed by an open-label phase in which all participants received the Nourkrin® product.^[36]Thom, E. (2006). Nourkrin: Objective and subjective effects and tolerability in persons with hair loss. Journal of International Medical Research, 34(5), 514-519. Available at: … Continue reading For the participants taking Nourkrin®, the study was 12 months long (6 months blinded and 6 months open), and for the participants taking the placebo, the study was 18 months long (6 months blinded and 12 months open). The study was completed on 55 people total of which 51 were men and 4 were women all aged 18+ (the researchers do not mention the upper age limit of the participants). Other than stating that all participants had hair-loss problems for at least a year before entering the study, there is no information regarding the type of hair loss the participants suffered from. There were also no exclusion criteria mentioned.

Data was collected through:

Hair counting – the researchers are not specific about how they counted the hairs, or how they made sure that they counted the same areas at each time point (to reduce bias). However, they do mention that data were collected from four areas of the head (forehead, crown, and the area surrounding the ears on both sides) in an area of 6.25cm2 and then totaled. Furthermore, this data was collected at the start of the study, and then again at the end of the blinded phase (6 months). There was a 35.7% increase in the number of hairs for the Nourkrin® treated group compared to the placebo group (1.5% increase), and the comparison was considered statistically significant. 

Self-perception questionnaires – the participants filled out self-perception questionnaires in which they were asked to score their satisfaction with the product they were using out of 10. After 6 months of treatment, the Nourkrin® treated group showed vastly higher satisfaction scores (5.9/10) compared to the placebo group (0.6/10). This further increased for the Nourkrin group® after the additional 6 months of the study duration in which they knew what they were taking (8.1/10).

The placebo group also filled out questionnaires after 6 months of switching to Nourkrin® and then after 12 months, and a substantial increase in satisfaction can be seen (6.2/10 after 6 months and 7.9/10 after 12 months).

Whilst on the surface, this study looks positive, there are some issues with the study design and the data that they show. Firstly, because we don’t know the type of hair loss that the participants are suffering from, we have no way of knowing if any of the improvement that they saw was from the hair loss issues resolving themselves. 

Furthermore, because of the way the hair count data was presented (as a mean of the whole group, rather than showing individual values), we don’t know if some of the positive data was due to a few people having really positive responses, versus a majority of patients experiencing a more mild benefit. Similarly, for the questionnaires, we don’t know if some people had very positive responses that pushed up the score.

Additionally, as this study was heavily skewed towards men, and there was no separation of the data collected from men or women, we can’t determine its efficacy in women. 

Perhaps the second study will give us a better idea…

Study Two

This study doesn’t appear to have been paid for by Nourkrin®, however, its parent company Pharma Medico International did supply the researchers with Nourkrin® Woman with Marilex® tablets.

114 women between the ages of 18-64 years and suffering from either telogen effluvium or female pattern hair loss took part in this open-label, subjective study.^[40]Wadstein, J., Thom, E. (2019). Treating Diffuse Hair Loss using Nourkrin® Woman (with Marilex) – An Open -Label, Subjective, Outcome Study on Hair Growth and Appearance, Self Confidence and … Continue reading

The exclusion criteria included

• usage of hair loss medications, supplements, or laser treatments
• people undergoing hair transplantation or other surgical scalp procedures
• usage of medications known to affect the hair cycle within the last 6 months
• people with any types of inflammatory alopecia or other significant dermatological conditions
• pregnant or breastfeeding women
• people allergic to fish or shellfish

Participants took 2 tablets of Nourkrin® for Women (600mg of Marilex®) daily for 6 months and were interviewed every 3 months with a “yes-no” questionnaire. They answered questions about hair growth, quality, and appearance over the course of the study, as well as whether there were any effects on participant self-confidence with their hair (Figure 7). Further questions were also asked about the safety and tolerability of the product.

As can be seen above, the vast majority of participants showed positive feelings towards their hair and towards the Nourkrin® product after 3 and 6 months of usage. The researchers concluded that treatment with Nourkrin® could be used by itself or in combination with other treatments for female pattern hair loss or telogen effluvium, however, they did not expand upon how they came to this conclusion With regards to safety, 7 participants did report adverse effects of a gastrointestinal nature (there’s no further information given), which disappeared after continuous use and did not cause any drop-outs from the study.

However, there are important caveats to note for this study:

• No placebo – so the results cannot be compared to someone who didn’t take the product.
• Open-label study – meaning that everyone knew what they were getting (further making it difficult to discern real effects from perceived effects).
• Relies on self-perception surveys – many people want their hair loss to get better, and so they may falsely perceive an improvement where there may not be such an improvement. Being enrolled in an active hair loss study could intensify that effect.
• Some patients had telogen effluvium which may have resolved by itself over the 6-month period.
• Does not feature any objective measurements such as phototrichogram for tracking hair count, thickness, or density.
• Yes-no questionnaires force participants to make a definitive choice, they may have only seen a small improvement.

One other potential issue with this study is that it claims to have been independently monitored and supervised by something called The World Hair Council. The World Hair Council states that it “is a global non-profit, non-trading network of leading healthcare professionals and experts dedicated to bringing a better quality of life to sufferers of hair growth disorders globally”.^[42]World Hair Council, (no date), About World Hair Council. Available at: https://worldhaircouncil.com/about/about-world-hair-council/ (Accessed: 26 January 2023

It should be noted however, that the authors of this article are part of the expert panel on the World Hair Council website, have written reviews that are posted on the Nourkrin® website and have co-authored/authored nearly all of the published articles that are posted on the Nourkrin® page. We can’t make assumptions as to what relationship exists between the study’s authors, Nourkrin®, and the World Hair Council. Still, certainly, these parties should make a definitive statement to rule out any potential conflicts of interest.

Study three 

This study doesn’t appear to have been paid for by Nourkrin®, however, its parent company Pharma Medico International did supply the researchers with Nourkrin® Woman with Marilex® tablets.

The third study, completed in 2020, included 67 female participants aged 18-65 with diagnosed androgenetic alopecia or telogen effluvium.^[43]Mattos, S.M, Thom, E., Wadstein, J. (2020). Nourkrin® Woman with Marilex® Enhances Hair Growth and Appearance and Improves Hair Confidence in Women with Diffuse Hair Loss from Brazil: An … Continue reading The study was open-label, 6 months long, and all participants took 2 tablets of Nourkrin® woman daily (which contained 600mg of Marilex®).

Exclusion criteria included

• People affected by a clinically significant condition (the types of conditions are not mentioned but we can possibly assume its the same as the previous studies)
• People taking medications known to affect hair growth during or within 6 months of the study
• Pregnant and breastfeeding women
• People allergic to fish or shellfish

Hair Growth and Appearance and Improves Hair Confidence in Women with Diffuse Hair Loss from Brazil: An Investigator-Initiated Clinical Study.  Journal of Clinical and Investigative Dermatology. 8(1), 1-4. Available at: https://doi.org/10.13188/2373-1044.1000063}}

Once again, participants showed remarkably high satisfaction scores after both 3 and 6 months of use. This study, however, suffers from many of the same issues iterated above for Study 2, such as the lack of a placebo, the fact that it was open-label, and the fact that they didn’t utilize any objective measurements for hair growth such as a phototrichogram. As well as being supported by the World Hair Council.

So, only one study in which the researchers use some form of objective data collection (although they don’t detail how they count their hair), and it is heavily skewed towards men. The second and third studies only have women involved in their studies and are only based on subjective consumer perception questionnaires. This leaves us to think that there really are too many variables involved to be able to definitely say whether Nourkrin® works in either men or women. 

Is Nourkrin® hair supplement safe?

Nourkrin states “There have been no known side effects in the more than 30 years that Nourkrin® has been available”.^[45]Nourkrin, (no date), Is Nourkrin Safe and Side Effect Free? Available at: https://nourkrin.com/what-are-proteoglycans/ (Accessed: 26 January 2023 However, the longest study that was completed lasted no more than a year, so we cannot say what the long-term effects may be.

If you are allergic to fish, you should not take this product as the proteoglycans in this product are made from fish extract.

Should I use it?

You may be a suitable candidate for Nourkrin® if you are:

• Suffering from hair loss
• Want to feel more confident in how you feel about your hair
• Are comfortable trying products with low levels of clinical data
• Have had no success with any other treatment for hair loss

If you fit these criteria, you may want to try Nourkrin® supplements provided that are aware that there are other products which contain marine polysaccharides such as Viviscal which are cheaper in price, and arguably have better quality clinical data – based purely on the fact that they actually have objective, quantitative data and placebo-controlled studies (although they also have their own problems).

Otherwise, our opinion is that there is not enough efficacy and safety evidence to recommend Nourkrin® at this current time. 

Recommendations to the company

Ideally, Nourkrin® should fund large-scale trials of its supplement, making sure that they provide details about the type of hair loss each participant has, as well as ensuring that there are males and females included. Furthermore, Nourkrin® should be looking to provide quantitative data outcomes including hair follicle count, hair thickness, and hair growth measurements, instead of relying on patient satisfaction surveys that can be open to bias. The trials should also be properly controlled with randomization and usage of placebos, as well as being pre-registered with patient numbers so that there is protection against just dropping data from patients that see no benefit. If they implement this, then we will be able to understand whether Marilex® and Nourkrin® actually work.

Final Thoughts

If you are comfortable trying products that do not have large amounts of clinical data, and you have had no success with other treatments, then Nourkrin® might be something you could consider experimenting with. 

We would suggest that Nourkrin® conduct larger-scale, pre-registered placebo-controlled studies that collect objective, quantitative data. If efficacy and safety were demonstrated in those circumstances, then we might have been able to recommend this product. As it stands, however, there is insufficient evidence showing that Nourkrin works.