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Hi everyone, and welcome back to Hair Loss Immersion. I’m Dr. Ghorbani, a plastic surgeon specializing in hair loss.
There’s a common concern circulating online, particularly in forums like Reddit, where people worry that finasteride might lower their testosterone and lead to muscle weakness.
This fear stems from the belief that finasteride reduces “male hormones.” Since testosterone is the most well-known male hormone, many assume it’s affected.
So, does finasteride actually lower your testosterone and weaken your muscles? Let’s dive into the facts.
Does Finasteride Lower Testosterone?
Finasteride is a medication that reduces DHT (dihydrotestosterone) levels by blocking the enzyme 5-alpha-reductase, which converts testosterone into DHT.
According to studies, taking 1 mg of finasteride daily can:
- Reduce DHT levels by up to 72%.
- Increase testosterone levels by 10-20%.
Here’s why:
When DHT formation is reduced, the testosterone that would normally convert into DHT remains in the bloodstream, leading to a slight increase in overall testosterone levels.
Conclusion: Instead of lowering testosterone, finasteride raises it. The idea that finasteride lowers testosterone is simply not true.
The Role of DHT and Testosterone in Muscle Development
When it comes to muscle health, testosterone is the primary hormone that matters—not DHT.
DHT’s main functions:
- Regulates body hair growth, skin health, and prostate function.
Testosterone’s main functions:
- Plays a crucial role in muscle growth and maintenance.
To illustrate this, there’s a rare genetic condition where individuals have a deficiency in the 5-alpha-reductase enzyme. These people have very low DHT levels but still develop normal muscle mass.
Conclusion: Reducing DHT with finasteride does not directly cause muscle loss.
Estradiol: The Overlooked Factor
Here’s where the confusion might arise:
While finasteride increases testosterone, it also raises estradiol levels by 10-20%. Estradiol, a form of estrogen, is present in both men and women, though women have much higher levels.
Estradiol’s role in men:
- Supports muscle mass.
- Helps regulate body fat.
If muscle loss were to occur while using finasteride, it would likely be related to this small increase in estradiol.
Good news:
- This estradiol increase remains within the normal physiological range for most people and is unlikely to cause any issues.
Lifestyle Matters
The potential for hormonal imbalances, including muscle loss, is higher in individuals with a sedentary lifestyle.
Regular physical activity helps maintain:
- Healthy hormone levels.
- Muscle strength and growth.
Even those who use steroids, which can increase estradiol levels by up to 400%, still manage to build muscle due to their active lifestyles.
Key takeaway: If you’re physically active, finasteride won’t hinder your ability to build or maintain muscle.
Is Finasteride Right for You?
Before prescribing finasteride, I always evaluate my patients’ health and lifestyle. This includes:
- Checking for sedentary habits.
- Assessing hormone levels.
In about 5% of patients, low baseline hormone levels may make finasteride less suitable, as it could lead to unwanted side effects. For these individuals, alternative treatments may be a better option.
Conclusion
Finasteride does not lower testosterone or directly cause muscle weakness. In fact, it slightly raises testosterone levels. Muscle health primarily depends on testosterone, and as long as you maintain an active lifestyle, finasteride should not negatively impact your muscles.