Finasteride is a prescription medication primarily used to treat hair loss and an enlarged prostate by inhibiting the enzyme 5-alpha-reductase.

However, its impact on hormonal health, particularly regarding testosterone levels, has been a topic of considerable discussion and research.

In this blog post, we’ll discuss whether finasteride lowers testosterone, exploring the science behind its mechanism and the implications for men’s health.

Understanding Testosterone and Dihydrotestosterone (DHT)

Testosterone and dihydrotestosterone (DHT) are crucial for male development and hormonal health, but they serve different purposes and have distinct effects on the body. Understanding the roles and differences between these two hormones is key to comprehending how treatments like finasteride work and their impact on your health.

What’s the difference between testosterone and dihydrotestosterone?

Testosterone is the primary male sex hormone, essential for developing male traits like a deeper voice and muscle growth. It supports overall male health, including bone density and red blood cell production.

Dihydrotestosterone (DHT), derived from testosterone, focuses on specific male characteristics and is more potent. DHT enhances traits like facial hair but can also lead to hair loss and prostate issues.

The main difference is testosterone’s broad health support versus DHT’s targeted, potent effects. Understanding this helps in managing the impacts of medications on these hormones.

Short-term vs. Long-term Effects of Finasteride on Testosterone

The effects of finasteride on testosterone can vary over different periods.


In the short term, starting finasteride primarily leads to a decrease in DHT levels, given its mechanism of inhibiting the 5-AR2 enzyme. As the body adjusts to these changes, individuals might not notice significant alterations in their testosterone levels. 

The period is crucial for observing how the reduction in DHT affects conditions like hair loss or BPH symptoms without dramatically altering the overall hormonal balance.


Long-term finasteride use continues to suppress DHT production, which can have protective effects against conditions like BPH.

A study assessing finasteride’s effectiveness against BPH in rats found that it not only reduced prostate enlargement but also lowered DHT, 5-AR2, and PSA levels. It suggests that prolonged finasteride use can beneficially modulate hormonal and other factors, including angiogenesis and reactive oxygen species, contributing to the prevention of BPH symptoms.

However, while DHT levels remain low with long-term use, testosterone levels generally stabilize, ensuring that muscle mass and strength are not adversely affected. It highlights finasteride’s targeted action and its capacity to manage conditions associated with high DHT levels without drastically affecting the body’s testosterone.

Side Effects of Finasteride Related to Testosterone Levels

While finasteride is targeted primarily at reducing DHT levels without directly lowering testosterone, it can still have side effects that seem related to changes in your hormonal landscape. It’s important to approach finasteride with a clear understanding of these potential side effects.

Reduced Libido

One of the more common side effects reported by finasteride users is a decrease in libido. This can be concerning, but it’s believed to be more closely related to the reduction in DHT levels rather than a decrease in testosterone. DHT plays a role in sexual desire, which may explain why some individuals experience this change.

Erectile Dysfunction

Similar to the impact on libido, some men taking finasteride report difficulties in achieving or maintaining an erection. While this might initially seem related to testosterone levels, it’s again thought to be due to lowered DHT, which can influence erectile function.

Mood Changes

Mood changes, including symptoms of depression and anxiety, have been reported in some cases. While testosterone is known to influence mood, these side effects might also stem from the psychological impact of experiencing other side effects or from the hormonal adjustments themselves.


Gynecomastia, or the development of breast tissue in men, is a less common but possible side effect. The condition is complex and can be influenced by imbalances in estrogen and testosterone levels. Since finasteride can slightly alter the hormonal balance, it may contribute to this risk in some individuals.

Schedule Your Free TRT Consultation Here

Does Finasteride Lower Testosterone Levels?

Finasteride does not directly lower your overall testosterone levels.

Instead, it specifically targets and inhibits the enzyme 5-alpha-reductase type 2 (5-AR2), which is responsible for converting testosterone into dihydrotestosterone (DHT). 

By reducing DHT levels, finasteride mitigates the conditions stimulated by this more potent androgen, such as hair loss and prostate growth.

Because finasteride’s action is focused on preventing the conversion of testosterone to DHT, some individuals might experience a slight momentary increase in circulating testosterone levels due to less of it being converted into DHT.

However, more studies have yet to be conducted to confirm finasteride’s little long-term effect on an individual’s testosterone levels.

Can you take Finasteride if you’re on testosterone replacement therapy (TRT)?

If you’re undergoing testosterone replacement therapy (TRT) and considering finasteride, it’s essential to have a detailed discussion with your healthcare provider.

Adding finasteride to your regimen can help mitigate the potential increase in DHT caused by TRT, addressing concerns like hair loss or prostate growth without negatively impacting the goals of TRT. 

However, the combination of TRT and finasteride requires careful monitoring to balance the benefits against any potential side effects, ensuring the treatments complement rather than counteract each other.

Always consult with a healthcare professional who understands your health history and goals to tailor the approach that’s right for you.


What happens if you take too much finasteride?

Taking more finasteride than prescribed can increase the risk of side effects, such as sexual dysfunction, mood changes, and even more severe health issues. It’s crucial to follow your healthcare provider’s instructions precisely and report any adverse effects.

Does stopping Finasteride increase testosterone?

Stopping finasteride typically does not lead to a significant increase in testosterone levels. However, DHT levels may rise as the drug’s inhibitory effects wear off. Your hormonal balance will gradually return to its pretreatment state.

Can I build muscle on Finasteride?

Yes, you can build muscle while taking finasteride. The drug primarily affects DHT levels without significantly altering testosterone, the key hormone involved in muscle growth. Maintaining a healthy diet and consistent exercise regime is essential for muscle development.

Optimize Your Hormonal Health with Best TRT

Navigating the complexities of hormonal balance can be challenging, but you don’t have to do it alone.

Best TRT, the leading online testosterone replacement therapy (TRT) clinic, stands out by offering specialized assistance to those navigating the intricacies of hormonal health.Our online clinic offers unparalleled convenience by facilitating easy access to professional healthcare support from the comfort of your home or anywhere you have internet access.

Schedule your free TRT consultation here and embark on a transformative journey towards hormonal balance and enhanced well-being.

author avatar

James Harrington

James Harrington stands as a leading authority in testosterone replacement therapy (TRT). With rigorous academic training and deep-rooted experience in health and wellness, he offers unparalleled expertise to Best TRT. His blend of scholarly knowledge and real-world experience makes him an indispensable guide for anyone delving into the intricacies of TRT.

Leave a Reply

Your email address will not be published. Required fields are marked *