Topical finasteride has gained popularity as a treatment for hair loss in recent years. Unlike oral finasteride, the gold standard is 1 mg a day. There are a wide range of topical finasteride concentrations used by people, ranging from 0.02% to 0.3% finasteride with 6% minoxidil.  So what is the best concentration for topical finasteride? Is 0.3% finasteride too high?

When topical finasteride was first started, it was 0.1%. The reason is very simple, 1 ml of 0.1% solution is 1 mg, the same amount as Propecia oral pills. 

That is why our products that require once a day usage, such as Dualgen-15 With PG Plus and Dualgen-15 NO PG Plus, have 0.1% topical finasteride.

We also have a solution that requires twice a day usage, we lowered the fin concentration to 0.05%, such as Essengen-6 Plus.

For the solution that only needs 0.5 ml a day, we increase the concentration to 0.2% (eg. Essengen-F), because 0.5ml of the solution is still 1 mg fin. 

We also have a product that has higher fin concentration such as Maxogen-X that has 7% minoxidil, 0.15% finasteride, and retinoic acid at 0.025%.

There is a well known study that investigated a 0.025% topical finasteride solution on scalp and serum dihydrotestosterone in healthy men with androgenetic alopecia. Please keep in mind that the topical solution (P-3074) used in this study is a gel solution, which is different from our solutions. In this study, 100µL, 200µL, 400µL, 1ml of P-3074 was applied to the scalp for one week, and then the scalp and serum DHT concentrations were measured. It was found that 100µL (0.23mg) and 200µL (0.455mg) (used once a day) decreased scalp DHT concentration as much as oral 1mg fin, but they lowered serum DHT much less than oral 1mg fin  (~25% vs 76%, See Table 1 below).

That is the reason why many people believe a 0.025% topical finasteride is the best solution, because 1 ml of such a solution is 0.25mg, which is similar to the amount of fin in 100µL (2.5%) in the study above.

When one interprets the results above, a few things to keep mind:

1. P-3074 used hydroxypropyl-chitosan, while most topical solutions available on the market including ours do not include this ingredient. Hydroxypropyl-chitosan helps form a film when the solution is applied to the scalp and it may affect the absorption.  

2. The number of subjects in the study is very small. The validity of the data needs to be confirmed by a larger study. 

Based on our experience, 0.3% is unnecessarily high.  One should only try 0.3% if a lower concentration topical finasteride solution does not work.  0.1% topical finasteride is sufficient for the majority of people. An even lower concentration such as 0.05% finasteride may work for many people. It is always a good idea to start with a low concentration topical finasteride such as Essengen-6 Plus if one has never used any minoxidil and finasteride combo before. If Essengen-6 Plus does not work after 3 months, one can switch to Maxogen-X that has Finasteride (0.3%), Minoxidil (8.0%), Retinoic Acid (0.001%), Hydrocortisone (1.0%).