Does Finasteride Lower Testosterone? Myths about Hair Loss Treatment

‍Does Finasteride Lower Testosterone? Myths about Hair Loss Treatment

As we grow older, we may experience symptoms associated with old age and hormonal changes. Male pattern baldness is one of those common signs of aging with finasteride being used as a go-to hair loss treatment. However, many medications we take have side effects — so is it true that finasteride can lower testosterone?

A relationship between low testosterone and hair loss has been long established with endocrine imbalances known to affect hair growth cycles. As the male hormone, low levels of testosterone can trigger hair loss while testosterone replacement therapy (TRT) can promote the restoration of scalp hair.

But how exactly is the interaction between finasteride and testosterone? We will explore together what type of drug finasteride is, what it’s being prescribed for, and how it can affect your testosterone. Let’s take a look!

‍

Causes of Hair Loss in Men

There are different types of hair loss — which doctors refer to as alopecia. For some people, hair loss only affects the scalp, for others, it can affect all body hair. In many instances, hair loss is the result of hormonal fluctuations that come as a natural part of aging. Baldness, however, is more common in men and is the product of excessive hair loss on your scalp.

The most frequent form of hair loss in men is male androgenetic alopecia (MAA) which can impact up to half of all men by age 50.

Androgenetic alopecia is hereditary and develops as you age. Other hair loss triggers encompass hormonal changes, such as fluctuations in your thyroid hormone. Hair loss can further be a byproduct of taking certain medications, including meds for depression and arthritis.

‍

Does Testosterone Cause Hair Loss?

While aging is commonly cited as a key contributor to hair loss in men, the truth is that our bodies undergo an array of changes as we get older — and as a result, we experience symptoms like hair loss.

Your testosterone levels naturally decline with age, decreasing roughly 1% every single year after age 30. Thus, testosterone deficiency is more prevalent in older men and goes hand-in-hand with older age.

While low testosterone and hair loss have a complex relationship, hormonal imbalances are known to lead to changes in your hair texture and growth rates.

‍

What is Finasteride?

In men, finasteride or proscar is used primarily for hair loss or enlarged prostate — a condition that is also known as benign prostatic hyperplasia (BPH). Finasteride typically treats symptoms of BPH, such as frequent urination, while simultaneously reducing the likelihood of needing prostate surgery. It also treats hair thinning and male pattern baldness.

Finasteride is a 5-alpha reductase inhibitor alongside the drug dutasteride, both of which are approved by the FDA (Food and Drug Administration) for BPH and male pattern baldness.

Alone in 2021, more than 8 million prescriptions were written for finasteride, which is taken orally — usually 5 mg daily for adults.

Several sexual side effects have been associated with finasteride, including possible changes in your mental health. Sexually, you may experience a decreased libido and struggle to get or maintain an erection. Finasteride may also cause depression and irritability.

‍

Finasteride for Hair Loss

Finasteride has been approved by the FDA for male pattern baldness and works by targeting a hormone responsible for stopping scalp hair growth. When you take finasteride for hair loss, you should expect it to take a minimum of three months to see results — but should see improvement during the first year.

While effective at increasing scalp hair growth, men taking finasteride don’t experience an increase in other body hair.

Studies show that finasteride decreases hair loss in 88% of men and helps hair regrowth in 66% of individuals. If you stop taking finasteride, you may lose hair you have regrown, and you may experience new hair loss.

‍

Does Finasteride Lower Testosterone?

Because finasteride and testosterone have a complex relationship, there is a myth that finasteride lowers testosterone but this is simply not true. In fact, finasteride blocks an enzyme called 5-alpha-reductase which prevents testosterone from being converted into dihydrotestosterone (DHT) — which actually causes more testosterone to be present in your bloodstream. 

What does that mean? It means that finasteride does not lower but temporarily increases testosterone levels. 

A long-term study that investigated 3,040 men, was conducted to understand the link between finasteride and testosterone in individuals diagnosed with BPH. The trial showed that finasteride treatment over a 4-year trial window led to higher levels of serum testosterone in the finasteride group when compared to men on placebo.

The study also found that the most significant increase in testosterone levels was observed in men with lower testosterone levels at the start of the trial.

A meta-analysis and review further looked into 11 studies with a total of 1,784 patients and found that while not all results were consistent and not all increase uniform, there were no findings regarding lowered testosterone levels. Instead, some studies indicated that testosterone levels in men with higher baseline testosterone remained simply unchanged.

Finasteride and Testosterone: Can You Take Both Together?

Research indicates that while finasteride can increase testosterone, long-term changes are unlikely. Many men with testosterone deficiency, therefore, continue taking testosterone replacement therapy (TRT) to balance out low T levels, while simultaneously taking finasteride for male pattern baldness or benign prostatic hyperplasia.

You should always consult with your doctor and monitor your serum testosterone levels regularly to verify if you’re still in need of TRT. However, when it comes to hair loss, especially age-related and hereditary hair loss, finasteride has been shown to be an effective solution.

Want to learn more about the impact of medications on your testosterone levels? Sign up for our newsletter to understand how your hormonal system interacts with the meds you take!