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The Hair Loss-Testosterone Connection
When I was diagnosed with pattern hair loss, the only thing I knew was that hair loss had something to do with testosterone. After a little research, I learned the following:
Dihydrotestosterone, or DHT, is a byproduct of testosterone. DHT levels are elevated in those with thinning hair. Because of this connection, DHT is often considered the cause of hair loss in men and women.
That's simple enough. I thought to myself, "If DHT is made from testosterone, and I have high DHT, that must mean my body is producing too much testosterone. This obviously means I am too manly for own good, so my hair is falling out."
I wasn't alone in this conclusion. A lot of hair loss sufferers, and even some researchers, think the same way.
It's an easy logical jump. But is it true?
If You Have Male Pattern Baldness, It Doesn't Mean You Have High Testosterone
The idea that all men with thinning hair have high testosterone doesn’t hold validity. This has been shown in a few ways:
- Studies have shown that balding and non-balding men have similar testosterone levels
- Aging males typically have lower levels of testosterone, but they have higher incidences of hair loss
- Male pattern loss has been observed in both high and low-testosterone males
Obviously, something else has to be going on here. Testosterone can't be the only implicating factor in hair loss. So what's actually happening?
DHT Is More Complicated Than Most People Think
The hormone DHT can be broken down into two categories. Firstly, there's serum DHT (the kind that circulates in your blood). Secondly, there's tissue DHT (the kind that binds to your skin, your scalp, and many other places in your body).
Many people assume that all kinds of DHT - both serum and tissue - are bad for your hair. But research on this is mixed.
Let's start with serum (blood) DHT. Some studies suggest serum DHT has no correlation with pattern hair loss. Others suggest that serum DHT is higher in young men without hair loss! This contradicts the widely preached dogma that DHT is universally bad for hair. Based on the evidence, serum DHT is either uncorrelated to or protective against male pattern hair loss.
But what about tissue DHT? Is tissue DHT correlated with baldness?
Yes. The distinction between serum and tissue DHT matters. It turns out that tissue DHT is elevated in the scalps of balding men. Tissue DHT in the scalp is linked to pattern hair loss. Where DHT collects in the scalp, hair loss tends to follow.
Beyond this, DHT gets extremely complicated.
For one, tissue DHT is associated with hair loss in the scalp, but paradoxically, tissue DHT also encourages body and facial hair growth. How can that be? How can tissue DHT encourage both hair growth and hair loss, depending on location?
Here's another paradox: while men's testosterone tend to decline with age, their serum DHT levels stay about the same (up until ~80 years old). At face value, that doesn't make much sense. DHT is made from testosterone. When testosterone decreases, we'd expect DHT to also decrease. But it doesn't. Why?
It turns out that testosterone (specifically, free testosterone) converts to many byproducts aside from DHT. As men's testosterone levels decline, their bodies also begin shifting the conversion of free testosterone toward DHT and away from other testosterone byproducts. This is how serum (blood) DHT levels remain constant, even when men's testosterone levels plummet.
The point of all this is... DHT's role in pattern hair loss is still debated. Men produce more DHT than women. Men bald more often than women. Tissue DHT is present in the scalps of balding men. But beyond that, it's still unclear whether DHT is the root cause of hair loss, or just a consequence of inflammation.
So, what happens when we extend our scope beyond DHT and ask, "Based on the evidence, is there a hormonal profile specific to a balding person?"
Yes. If we look beyond DHT and only consider our blood hormonal profiles, hair loss is closely connected to a few different hormonal imbalances. These hormonal imbalances vary based on the age, gender, and type of hair thinning from which a hair loss sufferer has. But typically, they all are suggestive of one thing: systemic inflammation.
Example #1: Young Men With Androgenic Alopecia (AGA) Have Similar Hormonal Profiles To Women With Polycystic Ovarian Syndrome (PCOS)
It might be shocking to discover, but young men with pattern hair loss have a hormonal profile akin to women with polycystic ovarian syndrome (PCOS).
Polycystic ovarian syndrome is a chronic condition that occurs in at least 10% of first-world women – most often starting around puberty. Its tell-tale symptoms: insulin resistance which precipitates hormonal dysregulation which precipitates the formulation of hair follicles (i.e., "cysts") on the ovaries.
The hormonal profiles of PCOS-affected women generally include elevated levels of prolactin, free testosterone (different from total testosterone), and a higher ratio of luteinizing hormone (LH) versus follicle-stimulating hormone (FSH). And fascinatingly, young men who are balding have the same hormonal profile: higher prolactin alongside a higher LH:FSH ratio.
What makes this incredibly interesting is that PCOS is also the leading chronic condition in young women compounding with pattern hair loss (androgenic alopecia). That means that the connection point between young male and female pattern hair loss sufferers is literally this hormonal profile.
And that's not the only thing this hormonal profile indicates. This same profile is associated, in the long-run, with chronic ailments like metabolic syndrome and heart disease. Why? Well, researchers aren't entirely sure... but the leading theory is that this specific hormonal profile is a barometer to gauge someone's degree of systemic inflammation (inflammation from within the body).
When we evaluate young male AGA against other diseases, this begins to make more sense. There's evidence that early-onset male AGA might even predict inflammatory-based diseases – like heart disease – later in life.
The takeaway: early-onset male (and female) AGA is associated with the same imbalanced hormonal profile... and this profile tends to suggest high degrees of systemic inflammation for both sexes.
And that's not the only hormonal profile associated with thinning hair.
Example #2: Testosterone:Estrogen Ratio Imbalances
While PCOS-affected women with pattern hair loss (AGA) tend to have higher free testosterone levels, so do peri-menopausal women who are losing their hair but aren't suffering from PCOS. And while younger balding men tend to have PCOS-linked hormonal profiles, they also have been found to have elevated estrogen levels.
So, it seems like in younger men males and older females, an imbalance of testosterone:estrogen is associated with pattern hair loss. How should we think about this? For younger men, the imbalance usually looks like this:
For men, even if testosterone levels stay constant, higher estrogen will imbalance the ratio, increase DHT conversion, and lead to hair loss.
For older women, the imbalance usually looks like this:
The ratio of testosterone:estrogen (t:e) – for both younger men and older women – can be used as a predictor of someone's overall systemic inflammatory load. With healthy t:e ratios, you're bound to have less inflammation. With imbalanced t:e ratios, you're more likely to have a lot of inflammation (at least if we reference normal ranges).
For men, the increasing rise in hair loss incidence should come as no surprise. With the current state of most first-world diets, men’s testosterone levels today are 22% lower than men of the same age 30 years ago.
For women, whom often experience hair loss after menopause, it should be no surprise that estrogen levels post-menopause drop by up to 90%. It looks like there really is a testosterone-estrogen connection.
What is in charge of regulating all of these hormones? Your endocrine system. More specifically, your thyroid.
Testosterone:Estrogen Levels Are (Partly) Regulated By Your Thyroid
Your endocrine system, but specifically your thyroid, is the body’s center for hormone production and regulation. If you have an underperforming thyroid, you probably often have cold hands/feet, poor circulation, nagging fatigue, irritability, a low body temperature, and imbalanced hormone levels. Another external symptom of a suppressed thyroid gland (or hypothyroidism) is a decrease in eyebrow hair thickness on the outside of your brows.
For many men, an underactive thyroid often coincides with a lower-than-desired testosterone:estrogen ratio (the inverse is true for women – though the levels are all still regulated by the thyroid). Poor thyroid function is also associated with a host of other diseases worth avoiding.
If I Improve My Thyroid, Will I Stop My Hair Loss?
It depends, but the short-answer: probably not.
While hypothyroid-related hair loss is certainly a huge issue in the first-world, it's also a different form of hair loss versus androgenic alopecia. Whereas hypothyroid-related hair loss leads to a hair shedding disorder, androgenic alopecia leads to hair follicle miniaturization. While both things cause hair loss, these two types of hair loss look totally different morphologically.
Whereas hair shedding disorders can resolve by addressing systemic inflammatory insults (diet, lifestyle, etc.), androgenic alopecia is only exacerbated by these same insults. Therefore, while improving your thyroid health via diet and lifestyle might resolve your testosterone:estrogen levels and hypothyroid-related hair loss... it won't resolve your androgenic alopecia.
Why? Because, again, when it comes to androgenic alopecia – it's not our circulating hormones that determine if we'll develop the condition! It's our scalp tissue hormones and the degree of DHT arriving to AGA-prone balding sites.
Long-story short: this is just one example of why our hormones and hair loss are just so complicated.
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.