Can Finasteride Make You Stronger? Understanding the Link

October 7, 2025 •

4 min read

While anecdotal reports and online forums debate the impact of finasteride on muscle, a 2012 study showed that inhibiting 5-alpha reductase did not adversely affect muscle mass or strength gains when used alongside testosterone supplementation. The question, 'Can finasteride make you stronger?' is often misunderstood, with the drug's mechanism of action focusing on hormone regulation rather than direct anabolic effects.

Quick Summary

This article explores whether finasteride can enhance muscle strength. It examines the drug's hormonal effects, including its impact on testosterone and DHT, and analyzes the scientific evidence regarding its effects on muscle mass, athletic performance, and potential side effects.

Key Points

Does not enhance strength: Finasteride is not an anabolic agent and does not directly increase muscle strength or growth.
Manages hormonal balance: It works by inhibiting the conversion of testosterone to DHT, which helps treat hair loss and BPH.
No impairment of gains: Scientific evidence suggests that finasteride does not prevent or impede muscle gains achieved through consistent training and diet.
Rare side effects: While rare, some users have reported muscle-related side effects like myalgia, but these are typically not common.
Training is key: Factors like training, diet, genetics, and recovery are far more influential on strength than finasteride.
Not a performance enhancer: Finasteride was previously banned by WADA not for performance-enhancing effects, but because it could mask other doping agents.
Minimal long-term hormonal change: Any initial rise in testosterone is often temporary, with long-term levels remaining stable.

Can finasteride make you stronger? The science behind the headlines

Finasteride is a widely prescribed medication primarily used for treating male pattern hair loss and benign prostatic hyperplasia (BPH). Its mechanism involves inhibiting the enzyme 5-alpha reductase, which converts testosterone into a more potent androgen, dihydrotestosterone (DHT). With this hormone-altering effect, it is understandable that questions arise regarding its potential impact on muscle mass and strength. However, the connection between finasteride and becoming stronger is not what many assume, and it is crucial to understand the distinct roles of testosterone and DHT in the body.

The hormonal cascade: Testosterone vs. DHT

To grasp how finasteride works, it's essential to distinguish between testosterone and DHT. Testosterone, produced predominantly in the testes, is the primary anabolic hormone responsible for muscle growth and strength. DHT, a more potent androgen, plays a crucial role in developing male reproductive tissues and influences hair growth patterns, but its direct impact on muscle anabolism appears to be distinct from testosterone's. While blocking 5-alpha reductase reduces DHT levels, it does not significantly decrease overall testosterone. In fact, circulating testosterone may even see a temporary increase as less is converted to DHT, though this often stabilizes over time as the body adjusts.

Scientific evidence on muscle and strength

Research has explored the relationship between 5-alpha reductase inhibitors and muscle performance. Several studies have concluded that finasteride, and its more potent counterpart dutasteride, do not significantly hinder the ability to build muscle or gain strength, especially when overall testosterone levels are adequate. For instance, a study in older men undergoing testosterone replacement therapy found that adding a 5-alpha reductase inhibitor did not affect gains in physical performance or changes in body composition compared to the group receiving testosterone alone. This suggests that testosterone, not DHT, is the primary driver of muscle hypertrophy.

Key findings from finasteride and muscle studies

DHT's lesser role: While some animal studies show DHT's potential role in fast-twitch muscle fiber activation, its contribution to overall muscle mass appears secondary to testosterone's.
No impairment of gains: Clinical trials have shown that men on finasteride can still achieve strength and muscle gains with consistent training and diet.
Temporary testosterone increase: Any initial, slight increase in testosterone from finasteride use is usually temporary as the body compensates by reducing production over time.
Focus on the bigger picture: Overall training, nutrition, and genetics remain the most significant factors influencing muscle strength and growth.

Rare muscular side effects

While the main body of evidence suggests no negative impact on muscle growth, there have been rare reports of muscle-related side effects associated with finasteride use. These reports are uncommon, with pharmacovigilance data confirming they occur in fewer than 1 in 10,000 cases.

Reported muscle-related side effects

Myalgia: Muscle aches or pain.
Myopathy: Muscle weakness.
Rhabdomyolysis: A serious and rare condition involving muscle tissue breakdown.

Health Canada's safety review of these cases acknowledged the risk but concluded it could not be conclusively linked in most instances. These side effects typically resolve after discontinuing the medication, but any persistent symptoms warrant immediate medical consultation.

Comparative effects of hormone manipulation


Aspect	Testosterone's Anabolic Effect	DHT's Androgenic Effect	Finasteride's Primary Action
Mechanism	Promotes protein synthesis and prevents protein breakdown in muscle tissue.	Drives androgenic traits, including hair growth (or loss) and prostate development.	Inhibits the 5-alpha reductase enzyme, blocking the conversion of testosterone to DHT.
Impact on Muscle Mass	High Impact: The most crucial hormone for muscle hypertrophy and strength.	Low Impact: Plays a minor, distinct role in muscle; blocking it does not significantly prevent muscle growth.	No Direct Impact: Does not interfere with testosterone's anabolic effects, and muscle gains are still possible.
Hormone Level Shift	Circulating levels may temporarily increase on finasteride.	Circulating levels are significantly reduced by finasteride.	Indirect Effect: Alters the ratio by decreasing DHT, but total testosterone levels remain largely stable long-term.

Factors influencing strength beyond finasteride

For most individuals, the decision to use finasteride will not be the deciding factor in their strength-training outcomes. A host of other variables exert a far greater influence on building muscle and getting stronger:

Training Consistency and Intensity: Regular, progressive resistance training is the single most important factor for building strength.
Nutritional Intake: A sufficient intake of protein, calories, and micronutrients is vital for muscle repair and growth.
Genetics: An individual's genetic makeup significantly influences their potential for muscle growth.
Sleep and Recovery: Adequate rest is critical for muscle repair and recovery.
Overall Health: Factors like stress, other medical conditions, and concurrent medications can all impact training performance.

Conclusion

While it is a common concern among fitness enthusiasts, the notion that finasteride can make you stronger is a misconception. Finasteride does not have direct anabolic properties that would enhance muscle strength or mass. By blocking the conversion of testosterone to DHT, it may cause a transient rise in testosterone, but this does not translate to greater muscle growth in a meaningful or long-term way, and most research indicates it does not impede gains either. In extremely rare cases, muscular side effects have been reported, but for the vast majority of users, finasteride's effect on hormonal balance does not pose a barrier to building strength through proper training and nutrition. Any individual with concerns about their physical performance should consult a healthcare provider to discuss their options and monitor their hormonal health.

For more information on the mechanism of finasteride, consult the FDA's approved label.

Frequently Asked Questions

No, finasteride does not increase muscle mass. While it can cause a temporary, slight increase in testosterone by reducing its conversion to DHT, this effect is not significant enough to lead to noticeable muscle growth.

For most users, finasteride will not cause a loss of strength or muscle. Studies have shown that men on finasteride can still build and maintain muscle mass, with strength gains primarily influenced by training and nutrition.

Finasteride inhibits the enzyme that converts testosterone into dihydrotestosterone (DHT), leading to a reduction in DHT levels. Less testosterone is converted, which may cause a transient rise in circulating testosterone, but overall testosterone levels tend to stabilize over time.

No, finasteride is not considered a performance-enhancing drug. It was once banned by the World Anti-Doping Agency (WADA) because it could mask the presence of anabolic steroids, but this ban was lifted in 2009.

Yes, you can absolutely still work out and build muscle while on finasteride. Your ability to gain strength and muscle will depend on standard factors like training intensity, diet, and recovery.

In very rare cases, some users have reported side effects such as myalgia (muscle pain), myopathy (muscle weakness), and rhabdomyolysis (muscle breakdown). These are uncommon and typically resolve when the medication is stopped.

While both are androgens, testosterone is widely recognized as the primary anabolic hormone for muscle growth and maintenance. DHT's role in muscle growth is less direct and significant compared to testosterone's.