Category Archives: Finasteride

Finasteride and Minoxidil Shedding is Normal

Hair Shedding Minoxidil Finasteride
Hair Shedding from Minoxidil and Finasteride.

Finasteride and minoxidil are the only two medications that are FDA approved for the treatment of hair loss.

Both work through different mechanisms of actions, and both can also cause unexpected temporary hair shedding episodes.

Finasteride and Minoxidil Hair Shedding

  1. Finasteride:
    • Mechanism of Action: Finasteride (Propecia brand name) is an oral medication that belongs to the class of drugs known as 5-alpha-reductase inhibitors. It works by inhibiting the action of the enzyme 5-alpha-reductase, which converts testosterone into dihydrotestosterone (DHT). DHT is implicated in the miniaturization of hair follicles in individuals who are genetically predisposed to androgenetic alopecia (AGA — aka male pattern baldness). Note that topical finasteride is also becoming very popular.
    • Hair Shedding: Some users may experience an initial increase in hair shedding during the first few months of finasteride treatment. This phenomenon (almost like telogen effluvium) is thought to occur as the drug affects the hair growth cycle.  In particular, the anagen growth phase is increased. Shedding is usually temporary, and most individuals observe regrowth and stabilization of hair loss after this initial phase.
  2. Minoxidil:
    • Mechanism of Action: Minoxidil (Rogaine brand name) is a topical medication that is applied directly to the scalp. While its exact mechanism of action is not fully understood, it is believed to promote blood flow to the hair follicles. This in turn prolongs the anagen (growth) phase of the hair cycle, increasing follicle length and thickness. Higher strength doses of minoxidil 10% and 15% are also available with prescription. Note that oral minoxidil is also becoming very popular.
    • Hair Shedding: Similar to finasteride, some users may experience an initial increase in hair shedding when starting minoxidil treatment. This shed phase is temporary and is often considered a sign that the medication is beginning to take effect. It is followed by a period of regrowth and stabilization of hair loss.


  • Shedding with both finasteride and minoxidil is usually transient and is not an indication that the treatment is ineffective.
  • These medications require consistent and long-term use to realize their benefits. Do not get scared with the temporary increase in hair fall.
  • It is crucial to consult with a healthcare professional before starting any hair loss treatment to determine the most suitable approach. And to address any potential side effects or contraindications.

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.