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The Zinc and Hair Loss Connection
Suffering from hair loss? You might think your hair thinning is due to hypothyroidism, a hormonal imbalance, or even dihydrotestosterone (DHT)… But what you may not know is that hair loss can also be a sign of a nutrient deficiency – specifically, zinc.
Zinc is an essential trace metal our bodies need to regulate hormones and even stave off conditions from infertility to macular degeneration. But zinc’s importance for hair health – and even zinc’s ability to reverse hair thinning – is only just now gaining attention.
But just how important is zinc for hair health (and hair regrowth)? Check out this case study.
A Case Study: Zinc & Diffuse Hair Thinning
These clinicians published a study in the International Journal of Trichology about a 28-year old female patient with widespread hair loss and scaly lesions. Her conditions had persisted for 2+ months.
Look at the severity of her hair thinning:
The photo on the left is suggestive of a type of hair loss known as diffuse thinning – or evenly spaced thinning throughout the scalp. This most commonly occurs in women, but it’s not exclusive to women (after all, diffuse thinning was also part of my hair loss diagnosis).
The photo on the right resembles three kinds of hair loss: 1) traction alopecia – hair loss as a result of the “pulling” of hair (typically from too tight of a ponytail). 2) telogen effluvium – hair loss often induced by stress — where many hairs simultaneously enter a “resting” and stop growing. And 3) a hair loss-related fungal infection. We can see some discoloration of her bald skin — which likely means that some sort of inflammation could be triggering the hair loss (for instance, inflammation from a fungus).
Regardless of the type of hair loss, this woman’s health is deteriorating. So what did these doctors do?
Treatment #1: Thyroxine (Thyroid Hormones)
The clinicians tested the patient for low thyroid hormone (hypothyroidism) and confirmed her thyroid levels were low. Then they attempted to treat her with thyroxine – a thyroid drug.
Hair loss is often a symptom of hypothyroidism. So it’s no surprise that this woman had 1) suppressed thyroid function, and 2) widespread hair loss on the scalp.
So did thyroxine improve this patient’s symptoms – or her hair loss? Unfortunately, no.
Treatment #1 Fails. The Patient’s Hair Loss Persists…
Thyroid supplementation did not improve this patient’s symptoms – or her hair health.
So what next? The investigators decided to do more blood work. The next step: checking the patient’s blood zinc levels. And this is where things get interesting…
Testing Serum Zinc Levels
For reference, normal blood (serum) zinc levels range from 66-144 mcg/dl. But if you’re familiar with health sciences, you know there’s a huge difference between what’s considered a “normal” range for nutrients… and what’s considered optimal.
In fact, optimal serum zinc levels are more likely in the range of 90-150 mcg/dl, at least according to the clinicians in this case study.
So what was this patient’s serum zinc levels? 62 mcg/dl.
Many doctors would see that number and think, “Oh, you’re barely below normal. Zinc probably isn’t an issue for you.” But these kinds of conclusions are becoming outdated. Why? Because new research suggests that someone’s nutrient needs change depending on their environment.
For example, someone with hypothyroidism (like this woman) might actually require more zinc than most other people – because zinc is required to synthesize thyroid hormones. As a result, a zinc deficiency might be the reason why this woman wasn’t seeing hair regrowth from thyroid medication.
At least, that’s what clinicians suspected. So they settled on a new approach…
Treatment #2: Thyroxine + Zinc + Multivitamin
The clinicians continued giving the woman thyroxine, but also started her on zinc monohydrate supplements – twice daily – 140mg capsules each (50mg of elemental zinc). They also gave her a multivitamin — since safe mega-dosing on zinc often demands the consumption of other nutrients like selenium and iodine.
So what were the results?
After one month, the scaly lesions on her face and scalp disappeared.
After four months on zinc, she regrew all of her hair. Don’t believe me? See for yourself.
So what can we glean from her hair recovery? The answers might not be what you expect.
Is Zinc The Answer To Fighting Hair Loss?
Maybe. Maybe not.
It’s tough to say with certainty how much of an impact zinc had on this woman’s hair. Why? Because there are two confounding factors: the multivitamin, and the thyroid medication. As a result, it’s short-sighted of us to say, “Everyone start taking zinc for hair loss!”
With that said, zinc is likely an overlooked (and necessary) element required for hair regrowth. So keep reading to uncover if you should take zinc, and if so, how much you should take, and why.
Supplementing with zinc? Be careful.
Some zinc supplements contain heavy metals. And too much zinc can cause copper deficiencies, neurological problems, and even worsen hair loss.
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Zinc & Pattern Hair Loss
Zinc works through a variety of mechanisms to promote hair health and even prevent hair loss. But for purposes of this article, we’re going to focus on zinc and its effects on…
- Thyroid metabolism
- DHT reduction
- Proteins required for hair shaft development
Hypothyroidism, Zinc, And Hair Loss
Widespread hair loss is often a symptom of low thyroid hormone levels (hypothyroidism). And our thyroids are also in charge of regulating our bodies’ hormones. As a result, hormonal imbalance, hypothyroidism, and hair loss often go hand-in-hand.
Interestingly, studies show that zinc is necessary for thyroid hormone synthesis.
The bottom line: without zinc, your thyroid can’t function properly. And without a properly functioning thyroid, your chances of hormonal imbalances and hair loss increase substantially.
Zinc Is Anti-Inflammatory
One of the key causes of pattern hair loss is chronic inflammation in the scalp.
Chronic inflammation leads to fibrosis (scarring) and calcification of scalp tissues and the blood vessels supporting the hair follicles. The end-result is reduced blood, nutrient, and oxygen supply flow to our hair, which over a series of years, results in hair miniaturization (and eventually hair loss).
One way zinc may prevent hair loss and improve hair growth is by reducing inflammation.
In fact, studies show that chronic zinc deficiency is associated with increased inflammation and the release of pro-inflammatory cytokines — or proteins responsible for sending more inflammatory cells to damaged tissues.
The net: if we’re inflamed and zinc deficient, our bodies are going to overreact to the inflammation. And when it comes to hair loss, this overreaction is something we absolutely want to avoid.
So, keep your zinc levels optimized. Otherwise, you’re setting yourself up for an inflammatory cascade (and potentially a further progression of hair loss).
Zinc Decreases DHT (Dihydrotestosterone)
Dihydrotestosterone (DHT) is a sex hormone closely linked to pattern hair loss. In fact, DHT is elevated in balding scalp tissues, men who can’t produce any DHT don’t go bald, and men deficient in the enzyme which converts testosterone into DHT never go bald.
And while there’s still debate over whether DHT is the root cause of hair loss – or merely just one of many causes – it goes without saying that if we want to keep our hair, it might be in our best interest to at least balance our scalp tissue DHT levels between balding and non-balding sites.
Enter zinc: a natural and potent DHT inhibitor.
DHT, 5-Alpha Reductase, And Zinc
DHT is synthesized from testosterone by an enzyme known as 5-alpha reductase.
If we block (or inhibit) the 5-alpha reductase enzyme, we can reduce DHT levels and potentially increase hair growth.
In fact, this is exactly how the hair loss drug Propecia (Finasteride) works. Propecia inhibits the 5-alpha reductase enzyme, and in doing so, lowers DHT (which can help slow, stop, or even partially reverse hair loss).
In addition, zinc also decreases the formation of something called NADPH. NADPH is a cofactor our bodies need in order to form the enzyme 5-alpha reductase. In other words NADPH is necessary for 5-alpha reductase to work.
Evidence suggests that zinc reduces NADPH production, thereby decreasing 5-alpha reductase activity. This ultimately results in lower DHT levels, which could also explain why zinc is so critical for hair health.
Zinc Fuels Transcription Factors Critical For Hair Growth
Transcription factors are sets of proteins that tell our cells which genes to turn on and off. In other words, transcription factors change our cells’ gene expression – telling each cell what to become and which functions to perform.
Interestingly, new research reveals that gene expression might be more critical than we think for disease development. In fact, gene expression might also be the critical factor for the development of hair loss.
Certain transcription factors are required to activate the genes our bodies need to use to develop hair shafts. For instance, the KROX20 transcription factor is essential for the development of a hair shaft. Without the KROX20 transcription factor, hair cannot grow.
Interestingly, KROX20 doesn’t just show up all on its own. It needs to be activated by certain inputs. Specifically, zinc.
KROX20 is what’s known as a zinc-finger transcription factor – meaning that it requires zinc to be activated. And given KROX20’s importance for hair follicle development, it’s in our best interest to avoid a zinc deficiency so that KROX20 can keep doing its job of maintaining our hair.
What You Need To Know About Testing For A Zinc Deficiency
Most doctors will measure your zinc levels with a blood (serum) zinc test. Unfortunately, this method is relatively inaccurate. Evidence shows that many people with mild zinc deficiencies often have normal serum zinc levels (like that woman in the above case study!).
In addition, zinc and another trace element – copper – have a balancing relationship with one another. Sometimes normal zinc levels can mask a copper deficiency (or too high of copper), and vice-versa. This makes testing for a zinc deficiency difficult, and it makes diagnosing a zinc deficiency even harder.
So if we suspect we’re zinc deficient, what should we do?
Well, let’s first look at the kinds of people who are most likely deficient in zinc.
90% Of Athletes Might Be Zinc Deficient
Athletes – or gym warriors – are extremely susceptible to a zinc deficiency. Why? Because their exercise habits means that their bodies require far more nutrients than their sedentary counterparts.
I’ve competed in athletics my entire life. I also grew up on a standard American diet. Knowing this, it’s no surprise that I was diagnosed with pattern hair loss at the ripe old age of seventeen. I was probably severely deficient in several nutrients… zinc being one of them!
Vegans And Vegetarians Are At A Higher Risk Of Zinc Deficiency
Studies show that, compared to omnivores, vegans and vegetarians have significantly lower zinc levels.
This shouldn’t come as a surprise. Animal-based foods like oysters tend to also have the highest bioavailable zinc. And despite the fact that some vegan-friendly foods – like pumpkin seeds – are high in zinc, this zinc isn’t that bioavailable due to the binding properties of others substances in seeds.
I’ve experimented with many diets. I’ve tried vegetarianism for a year. I’ve also done a few stints of veganism – all to see if the diet would improve my hair health. It didn’t. Was a zinc deficiency part of my lacking success? It’s impossible to say. Nowadays, I can’t help but wonder.
Bottom line: if you’re an athlete, chances are you’re zinc deficient. If you’re a vegan or vegetarian, chances are you’re zinc deficient. And if you’re a vegan athlete, we can pretty much guarantee you’re zinc deficient.
How Can I Tell If I’m Zinc Deficient?
We know that serum zinc tests are unreliable. So how can we tell if we’re zinc deficient?
Well, there is evidence to suggest that the concentration of zinc in hair is the most reliable sign of chronic zinc deficiency. Zinc levels are normally 150 to 240 mcg per gram of hair, but levels <70 mcg/g indicate zinc deficiency. So, you could just get a hair analysis test…
But one case study suggests that the best way to test for zinc deficiency might just be to start supplementing with zinc, and to start tracking if your symptoms go away.
So you can try that!
First, determine if you’re at risk for a zinc deficiency. Are you an athlete, a vegetarian, or a vegan? If so, you might be zinc deficient.
Secondly, are you exhibiting any of the symptoms of a zinc deficiency? For instance: hypothyroidism, cold hands / feet, depression, irritability, hair loss, or diffuse hair thinning.
If so, then you might be zinc deficient. That means that zinc supplementation might be a good option for you.
BUT please! Be warned…
Too much zinc is dangerous. If you’re going to supplement, you have to do it safely. Otherwise, you might worsen your condition and even cause neurological impairments.
How To Supplement With Zinc
Zinc is absorbed in the small intestine. And about 20%-40% of the zinc you ingest actually gets absorbed. Once absorbed, the majority of that zinc gets stored in your bones and muscles.
I don’t mean to sound preachy, but I still believe that the best way to take zinc is by naturally incorporating it into your diet.
Getting zinc from natural food sources ensures two important things:
- You make overdosing really hard – since you’re not eating a food concentrate, but rather a real food.
- You also consume zinc’s adjunct nutrients – like selenium (since zinc-containing foods often contain these nutrients as well).
Most meats and seafoods (like oysters) are great sources of zinc. Nuts and lentils might look like great sources of zinc, but the bioavailability of zinc from plant sources is debated. So if you want to maximize your absorption, you’ll probably want to go with animal foods.
What If I Want To Supplement With Zinc?
Go for it. But you have to do it wisely.
For instance, some zinc supplements contain high levels of cadmium – a metal that we don’t want to over-consume — especially for our hair health. (Again, this is just another reason why 99% of the time, I’m anti-supplementation.)
And here’s another challenge…
Most people can tolerate up to 100mg of zinc per day, but excessive doses of zinc can result in gastrointestinal symptoms such as abdominal pain, vomiting, and diarrhea. Even worse, people who mega-dose on zinc can also develop kidney damage, copper deficiencies, and even neurological impairments.
The takeaway: it pays to know how to supplement with zinc safely — which forms to take, which nutrient adjuncts to include, how much to take, and why.
To help you out, I decided to write up a free guide on how to supplement with zinc safely. Inside you’ll find:
- The optimal dosage for zinc
- The optimal form of zinc
- Which foods to avoid while supplementing with zinc
- Which supplements to pair with zinc for successful long-term supplementation
You can access it here (my thanks to you for reading this far!).
Summary: Zinc for Hair loss
Zinc is an essential trace element that supports the thyroid and is critical for over 300 enzymatic processes inside our bodies. It’s also needed for thyroid hormone synthesis, quelling inflammation, and even decreasing the conversion of testosterone into DHT. In fact, zinc is also necessary for the expression of transcription factors that control hair shaft development and maintain hair growth. All of these mechanisms help support our hair!
Case studies have shown that zinc supplementation can improve hypothyroidism and even lead to complete hair recovery in those who are unresponsive to thyroid medications and suffering from suppressed thyroid function.
Athletes, vegans, and vegetarians are at the highest risk for zinc deficiencies. But the reality is that anyone suffering from hair loss might benefit from increasing their consumption of zinc — either through natural foods, or a zinc supplement.
But if you’re going to supplement, you have to do it safely! Stay smart, get informed, and don’t buy the first zinc supplement you find online or in the grocery store. The zinc supplement guide I put together should help. Otherwise, just stick to natural foods and try to eat a few ounces of oysters weekly.
Rob English is a researcher, medical editor, and the founder of perfecthairhealth.com. He acts as a peer reviewer for scholarly journals and has published two peer-reviewed papers on androgenic alopecia. He writes regularly about the science behind hair loss (and hair growth). Feel free to browse his long-form articles and publications throughout this site.