The Independent Pharmacy

Can Finasteride (Propecia) Cause Weight Gain

Daniel Hurley
Daniel HurleyMPharm IPPharmacist Independent Prescriber

Reviewed on 11 Oct 2023

Experiencing hair loss can be a deeply distressing and emotional journey for both men and women. Male pattern baldness, also known as androgenetic alopecia, is the most common type of hair loss, affecting up to 70% of men by age 70. For those seeking treatment, finasteride (brand name Propecia) has become a popular option. Finasteride is a type of drug known as a 5-alpha-reductase inhibitor, which works by stopping the hormone testosterone from changing into another hormone called dihydrotestosterone (DHT), the hormone responsible for hair loss in male pattern baldness. By reducing DHT levels, finasteride helps stimulate hair regrowth and slow further hair loss.

However, the journey towards overcoming hair loss with finasteride might bring along concerns about potential side effects like weight gain, which can be an additional source of anxiety. Unexpected weight fluctuations can be worrying, so examining the evidence surrounding finasteride and weight is important.

At The Independent Pharmacy, we understand how frustrating such unexpected changes can be. But you're not alone, and we're here to support you on your journey - starting with understanding how things work and what are your options.

Here's what you need to know about Finasteride (Propecia) and its connection to weight gain.

Does Finasteride Cause Weight Gain?

Several medical studies have looked at whether finasteride causes weight gain or not. A major long-term study found no real difference in weight gain between people taking finasteride and people taking a placebo.

In another study that followed patients for up to 7 years, there wasn't clear evidence to show that those taking finasteride gained weight. Their body mass index, which measures body fat, did not go up compared to those not taking the drug.

Overall, most studies so far have not shown a clear link between taking finasteride and gaining weight. However, more long-term research on large groups of patients is still needed to know for sure.

Can the Way Finasteride Make You Gain Weight?

Finasteride works by blocking a hormone called DHT. DHT causes hair loss, so blocking it helps regrow hair. But finasteride does not seem to directly affect weight through its effects on hormones.

While finasteride can increase the levels of the hormone testosterone in the body, the usual amounts of this hormone don't result in weight gain. Finasteride also does not raise estrogen levels, which can influence fat storage. So, while finasteride changes some hormones, the evidence so far does not show these changes lead to weight gain.

Finasteride Versus Other Hair Loss Treatments

Looking beyond finasteride, other common hair loss medications like minoxidil (also available as Regaine) do not list weight gain as a side effect or clinical concern. In contrast, some emerging oral hair loss treatments like oral minoxidil have been linked to water retention and fluid weight gain in studies. However, more research is still needed.

So far, finasteride has one of the lowest risks for weight gain among hair loss treatments, with no clear causal relationship established. Still, individuals can respond differently to any medication, making monitoring with a doctor important.

Mitigating Potential Weight Gain

Even though there's no solid evidence linking Finasteride (Propecia) to weight gain, it's understandable to want to maintain a healthy weight during your treatment journey. Here are some steps you can take:

Lifestyle Changes

While finasteride does not seem to directly cause weight gain in most men, some may still experience mild fluctuations. Making healthy lifestyle changes can help manage weight.

Eating a balanced, nutrient-dense diet full of lean proteins, fruits, vegetables, and whole grains can provide the body with proper fuel for its metabolism. Reducing processed foods, sugar, and unhealthy fats also helps prevent weight gain. Additionally, staying adequately hydrated is key.

Regular exercise is also important. A combination of cardio, like brisk walking, strength training, and flexibility, boosts calorie burn. Aim for at least 150 minutes of moderate exercise per week, along with twice-weekly strength sessions, to aid weight maintenance. Getting adequate sleep improves metabolic regulation as well.

Doctor Consultations

If weight gain occurs while taking finasteride, have a discussion with your doctor. They can provide personalised guidance on managing weight through diet, exercise, and other lifestyle factors. Doctors can also determine if any adjustments to finasteride or additional treatments are recommended.

Alternative Hair Loss Treatments

For those who are concerned, exploring other hair loss treatments that have a lesser likelihood of affecting weight might offer peace of mind. Some alternatives to discuss with a doctor include:

  • Laser devices - Low-level laser light therapy is sometimes used to stimulate hair follicles. No major side effects have been reported.
  • Platelet-rich plasma - This treatment involves injecting a concentration of certain helpful substances from a patient's own blood back into the scalp to encourage hair regrowth. These injections have shown promise for hair regrowth. Requires multiple sessions.
  • Herbal supplements - Saw palmetto and nettle extracts may help block DHT. Limited evidence on effectiveness.
  • Microneedling - Using small needles to create minor skin wounds can prompt hair regrowth. Mild side effects like redness.
  • Hair transplants - Surgically redistributing DHT-resistant follicles is an option for permanent regrowth. An invasive procedure.

However, these alternative approaches have varying degrees of effectiveness and must be considered carefully. Thorough discussions with doctors are important to determine suitable alternatives if finasteride seems problematic.

Understanding Finasteride

Finasteride is a medication that falls under a group of drugs known for their ability to help with hair loss and enlarged prostate symptoms.

Finasteride works by blocking the enzyme 5-alpha-reductase, which converts the hormone testosterone into dihydrotestosterone (DHT). DHT contributes to hair loss and prostate enlargement. By reducing DHT levels, finasteride can reverse these conditions.

The standard dosage of finasteride for hair loss is 1 mg, taken orally once per day. It is available in generic forms and the brand name Propecia. Results can take 3-6 months to show and must be taken continuously for sustained benefits.

Common and Rare Side Effects

The most common side effects of finasteride, seen in about 2% of men, include decreased libido, erectile dysfunction, and ejaculation disorders. These sexual side effects typically resolve after stopping treatment. Less common side effects reported in fewer than 2% of men include rashes, breast tenderness and changes, testicular pain, and dizziness.

Very rare side effects mentioned in isolated cases include male breast cancer, hypersensitivity reactions, and depression. However, large clinical studies have not established definitive causation. Discussions with doctors are important to weigh potential risks versus hair regrowth benefits.

Overall, research does not clearly link finasteride to medically concerning levels of weight gain. Mild fluctuations are possible with any treatment, but major weight gain would be an unexpected reaction.

Moving Forward

The journey through hair loss can be emotionally taxing, but rest assured, there are solutions available that can pave the path towards regaining not just your hair but your confidence, too. Finasteride remains one of the most scientifically proven medications to stop hair loss and stimulate regrowth. While no treatment is perfect, finasteride provides hope to millions of men living with male pattern baldness.

However, making major health decisions like taking finasteride can be overwhelming. There is a lot of information to digest regarding effectiveness, side effects, alternatives, and more. Educating yourself is an important first step. Have open and honest conversations with doctors. They want to see you thrive just as much as you do.

No two people are alike. While finasteride may work wonders for some men, others may be better served by trying a different approach. Maintaining realistic expectations is key. Hair regrowth takes time and consistency. But committing to an informed treatment plan that’s tailored to your needs will serve you well.

A full head of healthy hair is within your reach, and with patience, the right guidance, and a supportive community, you're not alone on this journey. With a thoughtful strategy guided by medical expertise, you can find the right balance between results and your comfort with side effects. Trust in the process, stay diligent and don’t give up hope. This, too, shall pass. Your best days are ahead.

Frequently Asked Questions

Does finasteride affect body fat?

Based on current research, there is no evidence that finasteride directly causes increases in body fat or obesity. Studies have not found significant differences in body mass index or body composition between patients taking finasteride versus control groups. Any minor weight fluctuations are more likely attributed to lifestyle factors.

Does finasteride affect metabolism?

Finasteride is not known to directly alter metabolic rate based on its mechanism of action. The drug blocks DHT production but does not impact other hormones that regulate metabolism, like thyroid stimulating hormone. Individuals may experience mild shifts in metabolism after starting finasteride, but major metabolic effects are unlikely.

What are the possible side effects of finasteride?

Common side effects of finasteride (in about 2% of men) include decreased sex drive, erectile dysfunction, abnormal ejaculation, rashes, breast changes, testicular pain, and dizziness. Very rare side effects mentioned in isolated reports require further study. Weight gain does not appear to be a medically supported side effect.

Does hair get thicker after taking finasteride?

Yes, clinical studies show finasteride is effective at thickening individual strands of hair in men with male pattern baldness. By blocking DHT and shifting more follicles to the growth phase, finasteride helps improve hair density and diameter over several months of treatment in most men who respond.


Male Androgenetic Alopecia - Endotext - NCBI Bookshelf (

Serious complication of low-dose oral minoxidil for hair loss - PMC (

A healthy, balanced diet - British Nutrition Foundation

Physical activity guidelines for adults aged 19 to 64 - NHS (

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