Category Archives: Finasteride

Does Finasteride Work after 20 Years?

Dihydrotestosterone (DHT) inhibitor finasteride was first approved by the US FDA to treat hair loss in 1997. The original brand name from its US based manufacturer Merck was Propecia.

The only other drug that has ever been approved by the FDA to treat hair loss is topical minoxidil (brand name Rogaine). In Japan and South Korea, dutasteride has also been approved to treat hair loss.

Long-Term Finasteride Studies

Finasteride 10 Years
A time-series progression of hair growth from daily Finasteride use over 10 years in a Japanese patient. © Yanagisawa M (2019).

Although finasteride was approved to treat hair loss 26 years ago, there are very few studies in existence that even attempt to analyze 5-year plus results. I found two that covered 10 years.

It is extremely difficult to get hair loss sufferers to come back to the same clinic regularly for 10 years and have their scalps analyzed. Moreover, many patients tend to stop using the drug after some years due to side effects or loss of motivation. Some might also alter their dosage without consulting their physician.

Many hair loss patients also add other drugs and products into the mix. This makes it impossible to determine the exact solo impact of finasteride on their hair.

The image on the right is from a Japanese patient who is taking finasteride for his hair loss. It shows the results at first visit, followed by annual follow-up visits from years 1 through 10. He is part of a long-term study of 523 Japanese patients who took 1 mg/day finasteride to treat their androgenetic alopecia for 10 years.

According to the authors of this study:

“A high objective efficacy was demonstrated by the modified global photographic assessment score (MGPA). It revealed improvement and prevention of disease progression in 99.1% of the 532 Japanese men with AGA treated with 1 mg/day finasteride for 10 years.”

Amazingly, these Japanese men continued to see new hair growth even after years of finasteride 1 mg/day use. In fact, many patients even saw new hair growth at the 10 year mark! Furthermore, most patients saw an improvement from year 5 to year 10.

The average Japanese androgenetic alopecia (AGA ) patient in this study saw an improvement of approximately 1 Norwood scale grade after 10 years of treatment with finasteride. Side effects remained minimal even after such long-term use. I am surprised at such a high 99.1% success rate after 10 years. It is beyond amazing.

I always assumed that the human body develops some tolerance to finasteride after 10 years of use (just as with repetitive intake of antibiotics, alcohol etc). Moreover, finasteride only reduces serum DHT levels by 70% (and scalp DHT levels by 64%). Surely the other 30% keeps causing some damage to hair follicles?

Online anecdotal reports (from the English speaking world) suggest that a majority of long-term finasteride users seem dissatisfied in the long run. Perhaps the first point below explains this anomaly.

  • These same Japanese authors published an 801-person (5-years of finasteride use) study in 2015 that concluded that Japanese hair loss sufferers are much better responders to finasteride than are Caucasian men. For comparison, they cited a prior large-scale 1,553 person study on Caucasian men that showed a 48% improvement after 5 years. Nevertheless, Caucausian men are still great responders after 5 years. The same authors also did a 2.5-year report (3,177 patients) with similarly favorable results in Japanese men. A summary of their 2.5-, 5-, and 10-year results can be read here.
  • In 2011, a team from Italy published 10-year results of 1 mg/day finasteride use in 181 men. The overall results were also quite favorable in this report, although there were some significant diffference between various age groups of patients. After 10 years, almost 70% of patients who experienced growth in their first year experienced continued growth. Moreover, in 21% of cases, treatment continuation beyond 5 years provided even better results. All the more resons to not give up on finasteride if you are seeing no side effects.
  • A study on finasteride use for treating benign prostatic hyperplasia (BPH) for 7-8 years showed maintenance of results and low rates of side effects.

According to Dr. Robert Bernstein:

“Although finasteride will usually continue to work as long as you take it, it may lose some of its efficacy over time. Generally after about 5 years we may notice that the patient’s hair is starting to thin again and we will increase the dose slightly.

However, he cautions that even if someone keeps thinning while on finasteride, it does not necessarily mean that the medicine is not working. The same person might have thinned much more without taking the drug.

20 Year Results

I hope that our Japanese friends maintain their discipline and release a fourth study with 15-year results by 2025. I doubt that we will ever see anyone pubish 20-year results, but hope I am wrong. In the invaluable ongoing Japanese effort, the dropoff in patients counted from 2.5 to 5 to 10 years of follow-up was 3,177 to 801 to 523 respectively. By the 20 year mark, I do not expect more than 100 people will have returned each year, even if photos are taken remotely.

Based on the findings that I discussed in this post, I am encouraged to keep using my dutasteride (which is superior to finasteride and has a much longer half life). However, I just take one 0.5 mg pill every week due to a fear of side effects. I am also wary about the long-term effects of finasteride (and dutasteride) on estrogen and testosterone levels, although there is no evidence as yet of any major changes.

Make sure to also check out my past posts on finasteride and dutasteride dosage discussion; and on finasteride and low-dose dutasteride combination treatment.

Dutasteride Works when Finasteride Fails

In 2021, the single most important drug in the fight against hair loss remains Dutasteride (brand name Avodart). However, it is not approved for that use by the US FDA. I have written numerous past posts on Dutasteride to treat male pattern hair loss.

The most useful one remains my Avodart reviews for hair loss post due to the vast number of reader comments. Also see my posts on Dutasteride injections (also knows as mesotherapy).

Dutasteride v/s Finasteride Dosage and DHT Reduction
Dutasteride reduces more Dihydrotestosterone (DHT) than Finasteride.

Dutasteride more Potent than Finasteride

Every week I search PubMed for the latest papers on Dutasteride and hair loss. This week, I discovered an important new June 2021 study that was just published. It is titled:

“Change in hair growth-related gene expression profile in human
isolated hair follicles induced by 5-alpha reductase inhibitors: dutasteride and finasteride.”

The findings of this study are quite interesting and related to something similar that I published in 2014 (see old post at bottom). Note that this latest work was led by Japanese researchers and funded by GlaxoSmithKline (GSK), the manufacturer of Avodart.

It is encouraging to see GSK still interested in Avodart for hair loss. They will almost certainly not try to get the drug approved to treat hair loss in the US or EU. To date, Japan and South Korea remain the only countries where you can officially use Dutasteride to treat hair loss.

In the rest of the world, the drug is prescribed to treat enlarged prostates (BPH) in older men. For hair loss, you need off-label prescriptions. Also note that on average, side effects from Dutasteride are worse than from Finasteride.

Although GSK is headquartered in the UK, this particular research was affiliated with the company’s Singapore subsidiary. Professor Manabu Ohyama (who I have covered in the past) gave advice on the study protocol and methodology.

Key Findings

The key findings of this latest paper on Dutasteride (and Finasteride) include:

  • Dutasteride and Finasteride both suppressed the negative effects of testosterone on hair-related gene expression.
  • In particular, the gene expression for growth factors FGF7, IGF1 and WNT5a.
  • Dutasteride may have a stronger inhibitory potency to increase growth factor expression than Finasteride.
  • Dutasteride’s greater efficacy on hair growth in comparison to Finasteride is possibly due to the inhibition of 5α-reductase Type 1; or due to greater inhibition of 5α-reductase Type 2 by Dutasteride when compared to Finasteride. My note: most likely both issues are at play per next conclusion.
  • The authors claim that there results suggest that: “Type I 5 alpha reductase may play an important role in hair growth along with Type II 5 alpha reductase.

I forgot that this issue of the significance of Type 1 5α-reductase in relation to hair loss is still unresolved. My guess is that Type 1 is significant, but not quite as significant as Type 2. Dutasteride attacks both Type 1 and Type 2, while Finasteride only attacks the latter.

Make sure to also read my post on destroying androgen receptors on the scalp.

June 8, 2014

Dutasteride Works when Finasteride Fails

An interesting study by South Korean scientists was recently published in “The International Journal of Dermatology”.  It measured the effect of Dutasteride on men with androgenetic alopecia unresponsive to treatment with Finasteride.

They took 35 balding people who did not see any improvement while on Finasteride 1 mg/day for 6 months. They then put those same people on Dutasteride 0.5 mg/day for 6 months.  31 of those patients completed the 6 months of treatment.  Hopefully, the 4 who stopped treatment did not stop due to experiencing significant side effects.

Over three-quarters of these 31 patients saw at least some increase in hair count. Only 1 patient had a marked improvement, while 6 patients had a moderate improvement and 17 patients had a slight improvement. The remaining 7 patients did not see any improvement or worsening.

Side effects included transient sexual dysfunction in 6 patients (17.1%).