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The Hype On IGF-1 And Hair Loss
Hair loss forums often tout a connection between hair loss and a protein called IGF-1 (insulin-like growth factor 1). The belief: if we increase IGF-1, maybe we can slow, stop, or reverse pattern hair loss.
Unfortunately, forums never clarify exactly what “increasing IGF-1 for hair loss” means.
For instance, IGF-1 is expressed all over our bodies – our skin, blood, and saliva… But blood (serum) IGF-1 exerts different effects than skin IGF-1, and that exerts different effects than salivary IGF-1.
So which kind of IGF-1 is connected to hair growth? Which kind should we increase to stop hair loss? And most importantly — is there even a scientific consensus behind the IGF-1 and hair loss connection?
The answers aren’t straightforward.
In fact, IGF-1 is associated with both hair growth and pattern hair loss – depending on its “place” of influence. And if we go about increasing the wrong kind of IGF-1, we can do more harm than good.
The article reveals why. We’ll uncover what IGF-1 is, why it’s connected to hair loss, which kinds of IGF-1 to avoid, and how to increase IGF-1 the right way – to target hair growth.
What is IGF-1?
IGF-1 (insulin-like growth factor 1) is a protein / hormone resembling insulin. Our bodies make most of our IGF-1 in our livers. From there IGF-1 enters the blood stream where it either binds to other proteins or attaches to other tissues (like the skin or our organs).
IGF-1 is critical for hundreds of cell functions… from cell growth to bodily development to anabolic function. And when it comes to hair health, IGF-1 levels can influence hair strength, hair growth cycle, and even pattern hair loss.
IGF1 And Hair Health: The Evidence
Studies show that low IGF levels are associated with inhibited hair shaft elongation and hair follicle regression. Specifically, lower IGF1 is connected to weaker, brittler hair.
IGF-1, Laron Syndrome, And Hair Recession
Have you heard of a condition called Laron syndrome?
Sufferers of this disease have a mutation in a gene that codes for IGF-1. Specifically, Laron syndrome sufferers can’t produce much (or any) IGF-1. IGF-1 is critical for growth and development, so typically those Laron syndrome are shorter with weaker musculature. But in terms of hair health, Laron syndrome appears to impair hair growth and weaken hair.
For instance, Laron syndrome children often experience frontal hair recession and abnormal hair growth. Their hair is thin and easy-to-pluck. And young adults sufferers – especially males – often develop alopecia (hair loss) later in life.
What can we glean from this? In the absence of IGF-1, hair can’t grow as strong or healthy.
That’s some major evidence in favor of the IGF-1 hair loss connection. And here’s another.
IGF-1 And The Hair Growth Cycle
What is the hair growth cycle? A naturally occurring phenomenon describing when our hair follicles either shed, start growing, or continue to grow hair.
Hair growth cycles change based on stress, diet, genetics, and seasonality. But now, new research shows that our hair growth cycle might even be dependent on the levels of IGF-1 in our scalp tissues.
Research shows that human hair follicle cells produce IGF-binding proteins – and that these proteins fluctuate in relation to the hair growth cycle.
With that said, we can’t extrapolate this study and say, “If IGF-1 controls the hair growth cycle, then increasing IGF-1 will regrow our hair.”
Why? Because hair loss due to interruptions in the hair growth cycle is different from hair loss due to androgenic alopecia (male and female pattern hair loss). Hair growth cycle-related hair loss is usually the result of too many hairs entering a “resting” phase simultaneously. This is when someone undergoes a massive hair shed — or a condition known as telogen effluvium.
Telogen effluvium is not pattern hair loss. Why? Because telogen effluvium is just a hair shed, while pattern hair loss is a symptom of scarring.
So, is there evidence that IGF-1 is connected to scarring forms of hair loss… like male and female pattern baldness?
IGF-1 & Pattern Hair Loss
IGF-1 is closely connected to three scalp conditions which precede pattern hair loss:
- Chronic inflammation
- Elevated DHT
And by diving into IGF-1’s connection to each hair loss trigger, we can uncover which kinds of IGF-1 we should increase, and which kinds of IGF-1 might make our hair loss worse.
#1: IGF-1 And Chronic inflammation
The Chronic Inflammation-Hair Loss Connection
Inflammation activates signaling proteins. And certain signaling proteins – when turned on for too long – lead to the development of scar tissue at the inflammatory sites (the scalp). This is typically called fibrosis (or perifollicular fibrosis — scar tissue surrounding the hair follicles). And unfortunately, fibrosis reduces blood flow to the scalp skin tissues. This reduces oxygen levels (hypoxia) and nutrients to the hair follicles, which in turn miniaturizes the hair follicles. The end-result: pattern baldness.
So in this inflammatory process, how is IGF-1 involved?
IGF-1 Helps Counteract Inflammation
Studies show that IGF-1 is produced locally by cells in response to inflammation. IGF-1 also appears to have protective anti-inflammatory properties. In other words, IGF-1 reduces inflammation by influencing the production and actions of inflammatory signals.
There is also evidence that pro-inflammatory signaling proteins – like TNF (tumor necrosis factor) and interleukins – reduce the activity of IGF-1. Unsurprisingly, these TNF and interleukins are associated with the inflammation that precedes pattern hair loss.
The bottom line is this: IGF-1 and inflammation share a complex relationship. But research shows that IGF-1 is anti-inflammatory — and that IGF-1 may even help fight against the chronic inflammation that creates scar tissue and precedes hair thinning.
#2: IGF-1 And DHT (Dihydrotestosterone)
The DHT-Hair Loss Connection
While there’s no consensus that DHT directly causes hair loss, the following is clear:
- DHT is elevated in balding regions of the scalp.
- Men who can’t produce DHT never suffer from pattern hair loss.
The net: if we want to reduce our risk of pattern hair loss, we probably need to keep an eye on our scalp tissue DHT.
DHT Decreases IGF-1 Production
In skin cells (dermal papillae), DHT decreases IGF-1 production – which researchers directly attribute to a longer dormancy of hair follicles and impaired hair growth. In fact, the same researchers go so far as to suggest that increased DHT leads to hair loss because of DHT’s effects on lowering IGF-1.
While the research is limited, the evidence is clear: there’s a relationship between skin tissue IGF-1 and skin tissue DHT. Where skin tissue DHT increases, skin tissue IGF-1 decreases. And in rat models, this decrease leads to hair loss.
#3: IGF-1 And Calcification
The Calcification-Hair Loss Connection
Chronic inflammation doesn’t only lead to scarring… it also leads to something known as calcification.
This is when — as a result of inflammation — calcium deposits build up inside the blood vessels. If this happens in the vessels supporting our hair follicles, it reduces blood, oxygen, and nutrients to those follicles — which can lead to hair follicle miniaturization and pattern hair thinning.
IGF-1 May Protect Against Calcification
While the evidence is still mounting, IGF-1 may have a protective role against calcification.
Researchers recently published a study about a potential remedy for calcified heart valves. After discovering that calcified heart valves have significantly higher IGF-1 levels in the valvular tissue, they formed a hypothesis…
Maybe IGF-1 levels increased in these calcified valves as a protective mechanism against calcification.
To test their idea, the scientists evaluated rabbits treated with a medication called Sitagliptin. This medication increases blood (serum) levels of IGF-1. They discovered that rabbits receiving Sitagliptin had significant increased blood (serum) IGF-1 levels… and more importantly, improvements in heart valve calcification.
While this study isn’t directly related to scalp calcification or hair loss, it suggests something important: that blood (serum) IGF-1 may protect against calcification in other parts of the body (like our scalps)… and that high levels of serum IGF-1 may indicate that the body is fighting off heart valve calcification (or other forms of inflammation).
Should We Increase All Kinds Of IGF-1 To Reverse Hair Loss?
Unfortunately, it’s not that simple.
Let’s recap: we know IGF-1 is important for hair health. Why? Because complete absence of it – as in Laron syndrome – results in hair recession and thinner, weaker hair. We also know that DHT decreases skin tissue IGF-1, and that if we have higher blood (serum) IGF-1, this suggests we either 1) have calcification, or 2) are actively fighting it off.
So does that mean that increasing all kinds of IGF-1 will lead to hair regrowth?
In mice, yes! In humans, probably not.
In Mice: Most Kinds Of IGF-1 Increase Hair Growth
Studies show that mice given IGF-1 stimulate hair follicle growth in a dose-dependent manner.
Another study evaluated the effect of giving mice a local injection of IGF-1. The investigators discovered that IGF-1 injections increased hair follicle number and prolonged the growing phase of the hair cycle. The study concluded that IGF-1 is an effective stimulator of hair follicle development and that IGF-1 may hold promise as a hair loss treatment!
But don’t get too excited. If there’s one thing we know about hair loss research, it’s that almost everything regrows hair on mice… but that these effects rarely carry over to humans.
In Humans: Some Kinds Of IGF-1 Increase Hair Loss!
That’s right. Elevated blood (serum) IGF-1 might also be associated with vertex balding!
Remember: IGF-1’s effects are dependent on the tissue it influences. For example, IGF-1 promotes growth in muscle and fat tissues… but when IGF-1 is in our blood (serum), it influences metabolism (by altering blood glucose levels). These site-dependent effects carry over into human hair. The gist: in humans, high levels of blood (serum) IGF-1 aren’t linked to hair growth. Rather, they’re linked to vertex hair loss.
The More Blood (Serum) IGF-1, The More Vertex Balding
In 1999, a group of investigators published a study evaluating the relationship between serum IGF-1 levels and hair loss in men age >65. They determined that incremental increases in serum IGF-1 levels are associated with an increased risk of vertex balding.
At first, this seems paradoxical. But when we take a step back, this sort of makes sense.
Remember: we know from that heart valve study that blood (serum) IGF-1 increases to possibly protect against calcification.
And since calcification likely contributes to pattern baldness, it wouldn’t be surprising to see that men with vertex balding also have higher blood (serum) IGF-1 levels. In fact, high levels of blood (serum) IGF-1 is also associated with diabetes, heart disease, cancer, and several other conditions that all stem from chronic inflammation.
Knowing this, here’s a plausible theory: maybe these men with vertex balding have higher serum IGF-1 levels because serum IGF-1 is a response to inflammation. Therefore, we’d expect balding men (who are suffering from inflammatory conditions like scalp calcification) to have higher serum IGF-1 levels.
And just like with those rabbits – maybe if those balding men were given drugs to increase their serum IGF-1 even higher, they might see a decrease in calcification… and maybe even a partial reversal of vertex hair loss.
But then things get more complicated…
Bound Serum IGF-1 Versus Unbound Serum IGF-1
A separate group of researchers carried out a follow-up study on 45+ year-old men to measure vertex balding, serum IGF-1 levels, and a protein known as IGF binding protein 3 (IGFBP-3).
This study sought to clarify if it was really all blood (serum) IGF-1 that was correlated with vertex hair loss, or maybe just one type of serum IGF-1.
For reference, blood (serum) IGF-1 comes in two varieties: unbound and bound. Unbound serum IGF-1 isn’t attached to any other molecule or protein. Is free to navigate our bloodstream to any tissue site, then attach to that site and exert its effects on the cells.
However, unbound IGF-1 only makes up about 1% of the IGF-1 in our blood. The other 99% of blood (serum) IGF-1 is bound. This means it’s attached, or complexed, to other proteins… proteins like IGF binding protein 3 (IGFB-3).
So this leaves an important question… Is all blood (serum) IGF-1 correlated with pattern hair loss… Or maybe just one type of blood (serum) IGF-1?
One research team attempted to (sort of) answer this question when they discovered that older men with vertex balding express lower serum IGFBP-3… and higher serum IGF-1.
What’s the implication? A better predictor of vertex hair loss might not be the amount of serum IGF-1 in your body. Rather, it might be the amount of serum IGF-1 in relation to serum IGFB-3… or to extrapolate, the amount of unbound serum IGF-1 versus bound serum IGF-1.
Unfortunately, there aren’t more follow-up studies, so we can’t say much more than that.
Any Other Evidence That IGF-1 Might Increase Hair Loss?
At a first glance, yes. There’s evidence that IGF-1 can increase DHT in certain tissues. But when we dive deeper into the data, it becomes clear why we can’t extrapolate these findings as evidence that IGF-1 “causes” pattern hair loss.
IGF-1 Might Increase 5-Alpha Reductase (And Thereby DHT)
Remember: DHT is a hormone associated with pattern hair loss. DHT is higher in balding scalp regions. And in the absence of DHT, men don’t suffer from pattern hair loss.
DHT is made from testosterone. Our bodies convert testosterone into DHT by using an enzyme called 5-alpha reductase. In fact, this very enzyme is how hair loss drugs like Propecia fight hair loss: they reduce the activity of 5-alpha reductase, and in doing so, reduce the amount of DHT in the body and scalp.
Ironically, there’s evidence that IGF-1 actually increases 5-alpha reductase (and maybe even encourages DHT conversion).
This study found that IGF-1 increases the activity of 5-alpha reductase in the skin. But before we panic, please keep this in mind:
- This study was conducted in a test tube (in vitro), not in live subjects
- The investigators used human and rat skin cells
- They evaluated scrotal skin cells, not skin cells in the scalp
On top of that, the relationship between DHT and hair loss is complicated, and paradoxical.
So let’s put this study into context.
If DHT increases hair growth in pubertal regions, and this study was done in scrotal cells… Then in a way, it’s consistent for IGF-1 to increase 5-alpha reductase (and thereby DHT) in scrotal cells. Why? Because scrotal skin cells develop hair during puberty, and increased DHT in this region actually increases hair growth.
So maybe skin tissue IGF-1 is still correlated with hair growth – despite what appears to be conflicting evidence here.
Which leads us back to our original question…
Should We Increase IGF1 For Hair Growth?
Yes. But we need to get specific about which type of IGF1, and why.
Which Kind Of IGF-1 Should We Increase To Support Hair Growth?
The evidence suggests that blood (serum) IGF-1 is elevated in those with vertex balding. This makes sense, because high serum IGF-1 levels are correlated with several inflammatory diseases, and high serum IGF-1 is also indicative of the body trying to fight against calcification (inflammation and calcification are two triggers of hair loss).
We also know that when we account for the DHT paradox, skin tissue IGF-1 is consistently associated with early hair development and healthy hair growth.
So what’s the takeaway?
If we want to increase IGF-1 to fight against hair loss, we should focus on increasing skin tissue IGF-1. And if we have high blood (serum) IGF-1, evidence suggests we’re probably inflamed.
So when using IGF-1 to fight hair loss, we need to do two things: 1) increase scalp skin IGF-1 levels, and 2) get blood (serum) IGF-1 levels down to normal levels.
How Do We Increase Skin Tissue IGF-1?
Research here is still ongoing. But interestingly, if we stimulate neurons that sense pain and heat sensitivity in our gastrointestinal tract and skin, these neurons release compounds that then signal for IGF-1 to arrive at the “stimulated” sites.
That means if we apply heat or induce pain in our scalp skin, we can signal these neurons to send more IGF-1 to our scalp skin and maybe even promote hair growth.
Sound crazy? This is exactly how researchers at Japan’s Anti-Aging Solutions are approaching a cure for hair loss. Their belief is that by simultaneously decreasing DHT and increasing skin-level IGF-1, hair follicles will reactivate and lost hair will regrow.
If true, this would explain the incredible hair regrowth results one reader experienced from doing years of intense massages + rosemary oil. The intense massages stimulated pain receptors to send more IGF-1 to the scalp. The rosemary oil decreased scalp tissue DHT. The result: major hair recovery.
How Do We Decrease Blood (Serum) IGF-1 To Normal Levels?
One of the most common causes of serum IGF-1 overstimulation is our diet.
The western diet is high in carbohydrates (grains and sugar) as well as dairy products. Unfortunately, westernized carb-heavy foods are also considered hyperglycemic since they can elevate blood glucose levels.
The problem with dairy and high-carb, hyperglycemic foods is that these both lead to the overstimulation of blood (serum) IGF-1. Over time, chronically elevated blood glucose and serum IGF-1 levels are associated with several chronic diseases – specifically, diabetes.
This isn’t necessarily to the fault of IGF-1 alone. Remember, it’s more likely that these food choices contribute to chronic systemic inflammation… and as a response to that inflammation, our bodies increase IGF-1 to “protect” against its consequences (like fibrosis and calcification).
To put it simply, our goal shouldn’t be just to lower serum IGF-1. It should be to lower systemic inflammation – and to gauge our progress by measuring if our serum IGF-1 levels are within normal ranges.
The bottom line: if you’re suffering from hair loss and you have high serum IGF-1 levels, you should probably reevaluate your dairy intake and high-glycemic food consumption. Doing so might help improve your hair health.
What Diet Is Best For Bringing Serum IGF-1 Down To Normal Ranges?
Studies show that a paleolithic diet can help prevent high glucose levels and the conditions that precede increased serum IGF-1. This is because this diet excludes hyperglycemic carbs like white breads, pastas, and processed sugars. Paleo-based diets also typically include a higher-than-average protein intake. And in people who have low serum IGF-1 levels to protein malnutrition, a high-protein diet tends to also help bring serum IGF-1 back up to normal.
With that said, I don’t want to the “diet” police. Everyone’s different, and some people trying vegetarian or vegan diets also tend to have perfectly normal levels of serum IGF-1.
With that said, I do have one warning: be careful about going ketogenic (very low carb). Ketogenic dieters are often prone to hair loss due to their propensity to under-eat — and consistent under-eating can trigger hypothyroidism and a host of other ailments. Interestingly, ketogenic dieters have lower serum IGF-1 levels. So, if you can do ketosis correctly (and avoid a calorie deficit – which is hard!), you might be just fine.
Realistically, our objective isn’t to skyrocket your IGF-1 levels… It’s to get serum IGF-1 within healthy ranges – like what JD Moyer does (one of this site’s success stories) — and to simultaneously increase skin tissue IGF-1 in the scalp skin. That combination is probably our best bet towards utilizing IGF-1 for hair growth.
Any Downsides To Greatly Increasing IGF-1?
Our bodies make IGF-1 on an as-needed basis — starting with our pituitary gland. When our pituitary gland releases growth hormone, that growth hormone reaches the liver and then, through a series of mechanisms, stimulates IGF-1 production.
That IGF-1 then enters into our blood stream, where 99% of it gets complexed to binding proteins (like IGFBP-3)… leaving the remaining 1% to exert effects on other tissues.
The net: if we produce excessive growth hormone, we’ll also likely produce excessive IGF-1. This is the exact opposite of Laron syndrome, and if we want to know what this does to our body… look no further than Andre The Giant.
Andre The Giant was a famous wrestler who suffered from a pituitary gland tumor that made him produce excessive amounts of growth hormone all throughout life. This led him to develop a disorder called gigantism.
While the disease eventually led to complications that resulted in Andre The Giant’s death… it’s important to note: Andre had great hair! Just look at him here:
With that said, don’t go wishing for a pituitary tumor in hopes of preserving your hair. The detriments of the disease outweigh the benefits of keeping your hair into your later years (in fact, with gigantism, you’ll likely never see “later” years — as most sufferers never make it to the age of fifty).
Summary: IGF-1 And Hair Loss
IGF-1 is a protein / hormone that is necessary for hair growth and hair development.
When it comes to increasing IGF-1 to fight hair loss, evidence suggests it’s better to increase scalp skin tissue IGF-1 and decrease excess serum IGF-1.
We can increase scalp skin IGF-1 by invoke inflammation (or pain) in the scalp – like with intense massaging, or dermarolling.
We can decrease excess serum IGF-1 by minimizing our intake of dairy and high-glycemic foods. In fact, serum IGF-1 seems to be more closely associated with chronic, systemic inflammation — which is why it tends to increase on diets that are pro-inflammatory. So eat an anti-inflammatory diet to help get those levels back to normal.
Finally, some researchers believe the key to reversing hair loss is to simultaneously decrease scalp DHT while increasing scalp skin IGF-1. If true, this might explain the hair regrowth results of a past reader who did intense massages + a rosemary oil topical. The massages increased scalp skin IGF-1, while the rosemary oil topical decreased scalp skin DHT.
That’s it! Questions? Please reach out in the comments.
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 five 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.