Can Testosterone Injections Cause Hair Loss?
Reviewed by Katelyn Hagerty, FNP
Written by Our Editorial Team
Hmmmm…is that more hair than usual circling the shower drain? Or are you just being paranoid?
The truth is, male androgenetic alopecia (AGA) — also known as androgenic alopecia or male pattern baldness — affects a whopping 30 to 50 percent of males by age fifty.
It’s the most common form of hair loss and mainly affects hair around the temples and front part of the scalp. It’s also permanent.
Look, whether your hair vibe is more George Constanza or Jean Luc Picard, we think you’re handsome regardless of what you’ve got on your noggin. But we also get that the mere thought of hair loss can be anxiety-producing.
So, what causes hair loss? Many factors can influence hair growth and shedding. But genetics and male sex hormones like testosterone play a key role in the development of AGA.
In this article, we’ll dig into what can cause hair loss and look at the link between testosterone and hair loss. We’ll cover prevention strategies for hair loss on testosterone.
Understanding the Hair Growth Cycle and Causes of Hair Loss
You probably don’t think much about how your hair grows. It just kinda comes out of your scalp, right? Surprise, surprise. It’s actually more complex than that.
The hair growth cycle involves three distinct phases:
Anagen. The growth (anagen) stage is when new hair fibers actively form within the hair follicles. What you might not know is that this process can last several years. TL;DR: Hair growth definitely doesn’t happen overnight.
Catagen. The transition (catagen) phase signals the end of active growth. It can last several weeks.
Telogen. The resting period (or telogen phase) is when hair follicles become dormant. At any given time, up to 15 percent of the hairs on your body (including facial hair, arm hair and even chest hair) are in the telogen phase. This stage can last up to a year.
Shedding hair every day is normal — up to 200 strands, give or take. Shedding more than this might indicate an underlying hitch in the hair growth cycle.
External and Environmental Causes of Hair Loss
Many factors can disrupt the hair growth cycle and lead to increased shedding. This includes:
Menopause (in females)
Tight hairstyles (bye-bye, man bun)
But in the case of male pattern baldness, hormones and genetics are at play.
Hormonal Causes of Hair Loss
Let’s start with how hormonal treatments can mess with your T-levels.
If you’re struggling with erectile dysfunction, it’s not uncommon to fret about your testosterone levels. After all, there’s a link between low testosterone levels and issues like erectile dysfunction, low sex drive and poor sexual wellness.
Low-T is more common in older men. But conditions like diabetes, autoimmune disease, thyroid disease and testicular cancer (or injury) can increase your risk at any age.
The following can also cause a temporary dip in T:
The good news? It’s treatable!
Healthcare providers commonly treat low-T with testosterone replacement therapy (TRT) — also known as testosterone injections. But TRT comes with potential side effects, and in some people, it may trigger hair loss.
So, high T = hair loss?
Actually, that’s not the whole story.
One 2017 population study in Northeastern Germany looked at the relationship between sex hormones and hair loss in men. It found no link between male sex hormones and male hair loss.
Researchers noted that this backs up previous research suggesting that developing bald spots from male pattern baldness might have more to do with sensitivity to male hormones than the hormone levels themselves.
It turns out genetics influence how sensitive your hair follicles are to circulating dihydrotestosterone (DHT). DHT is a byproduct of testosterone and one of the most potent androgens (male sex hormones).
Your body produces testosterone. As a byproduct of testosterone production, it converts a small amount of that testosterone to DHT by way of the 5-alpha reductase enzyme, which is found in small amounts in the body.
In young males, the body needs DHT to ensure the healthy development of the genitals and prostate, along with secondary sex characteristics like voice, muscle mass and body hair.
As an adult? DHT doesn’t really have a large job to do, and it can cause problems, like male pattern hair loss. In fact, researchers have found more DHT in balding scalps compared to non-balding ones. But not every guy’s hair follicles are ultra-sensitive to this sex hormone.
The more testosterone you produce, the higher the levels of DHT in your body. That’s not necessarily a death sentence for your hair, but it is a fact.
DHT can attach to receptors in the scalp and gradually shrink hair follicles until they can no longer produce hair — a process known as follicular miniaturization.
But what ultimately influences whether DHT has drastic effects on your hair is how sensitive your body is to DHT — that’s where genetics come in.
If you have a genetic predisposition to DHT sensitivity, too much of it can wreak havoc on your hairline.
Coming to a theater near you: Honey, I Shrunk My Hair Follicles. The villain? DHT.
Does High Testosterone or TRT Cause Hair Loss?
Okay…if DHT is a byproduct of testosterone, does that mean high testosterone levels can cause hair loss?
Is testosterone — gasp — bad?
Nope. High testosterone and testosterone injections (TRT) don’t directly cause male pattern baldness.
Increases in testosterone, natural or from testosterone boosters, don’t necessarily cause androgenetic alopecia. But if your hair follicles are more sensitive to DHT because of a genetic predisposition, you might be more likely to experience hair loss as a result of higher levels of DHT or testosterone injections.
Hims has helped thousands of men regrow their hair
How to Prevent Hair Loss While Taking Testosterone
We’ll say it again: Taking testosterone doesn’t mean you’ll definitely experience hair loss. Male pattern baldness isn’t about the amount of T in your body but whether your hair follicles have a higher sensitivity to DHT.
Though this increased sensitivity is genetically determined, there are a few steps you can take to treat and minimize your risk of hair loss.
Ask a healthcare provider about the following treatment options for hair loss:
Oral finasteride. Finasteride is an FDA-approved treatment for AGA (at a dosage of 1 milligram per day). Healthcare professionals also prescribe finasteride tablets for benign prostatic hyperplasia (BPH), aka an enlarged prostate. How does it work? It stops the body from converting testosterone into DHT — by about 70 percent.
Topical treatments. Not a fan of swallowing pills? Opt for one of these topical prescription medication treatments instead:
Topical finasteride and minoxidil spray. We’ve covered how finasteride works, so let’s talk about minoxidil. Experts don’t really know exactly how minoxidil (generic Rogaine®) works, but it appears to stimulate hair growth by shortening the telogen phase and lengthening the growth phase. Topical finasteride and minoxidil formulas come in liquid form. FYI: Evidence suggests that topical finasteride has the same effectiveness as oral finasteride, and it may be a better option for a receding hairline versus other types of hair loss.
Minoxidil foam. This topical minoxidil foam contains the same medicated ingredient in minoxidil spray but in a mess-free formula.
Minoxidil solution. This unscented minoxidil liquid solution is ideal for targeting hair regrowth on the crown or vertex areas.
Low-level laser light therapy (LLT). Lasers? Don’t those usually remove hair? Unlike the lasers that remove body hair, LLT involves low-intensity light to stimulate cellular activity — including in the hair follicles. In one 24-week study, 40 participants received daily treatments with a helmet-style LLT device or a sham device. After 24 weeks, those who received LLT therapy were found to have greater hair density and thickness.
Hair transplant. According to the American Academy of Dermatology (AAD), you’re a good candidate for a hair transplant if you have enough healthy hair on your scalp and can still grow hair in areas where you’re experiencing hair thinning. The only problem is, as you might guess, hair transplants can be costly and generally aren’t covered by health insurance.
Remember when we talked about the hair growth cycle and how the growth phase can last years? That means your day-to-day lifestyle choices can have a real impact on hair health.
Healthy lifestyle habits won’t stop hair loss, but they can make your hair more resilient and less likely to shed.
Get your vitamins. Proper nutrition is key to a healthy body from head to toe — that goes for your hair, too. Many vitamin deficiencies can make your hair more vulnerable to breakage and shedding. Your healthcare provider may recommend supplements like biotin to address any deficiencies that might be causing your hair loss.
Keep a lid on stress. You’ve probably heard it a million times: Stress is bad for you! In severe cases, it can trigger temporary hair loss, known as telogen effluvium.
Be gentle on your hair. Whether you have long, flowing locks a la Fabio or are rocking a buzz cut, taking proper care of your follicles can help reduce the damage that could contribute to breakage and shedding. Regularly washing with a product formulated for your hair/skin type can help prevent dryness that leads to brittle, shed-prone strands. You’ll also want to keep chemical treatments and dyes to a minimum.
Shop by treatment options
No matter the treatment plan, the best place to start is somewhere. Early action is the best hair loss prevention.
The Link Between Testosterone and Hair Loss
Not everyone sportin’ a bald head is intentionally doing so, action movie hero-style.
It’s all about confidence in the end, but there’s no getting around it: Dealing with male pattern baldness can be stressful. It’s pretty common, though — 30 to 50 percent of men will be affected by AGA by age 50.
How does testosterone factor in?
High levels don’t necessarily translate to hair loss. High testosterone isn’t a direct cause of male pattern baldness, but you can get a blood test to see if you have normal testosterone levels.
Some people are more sensitive to DHT. Sensitivity to this potent byproduct of testosterone makes some folks more likely to experience hair loss in response to higher levels of testosterone.
The bottom line? It’s genetic but treatable.
While you can’t do anything to change your genetically predetermined sensitivity to DHT, treatments for male pattern hair loss are available.