I have discussed Minoxidil many times on this blog in the past since it is one of only two drugs officially approved by the US FDA to treat hair loss. Most men use 5% topical Minoxidil foam and apply it to their scalps twice per day. For those who get adverse reactions, dosage is sometimes reduced to once per day. Very few people use oral Minoxidil to treat androgenetic alopecia.
Unbeknownst to many, Minoxidil was originally approved in 1979 as an oral medication (brand name “Loniten”) to treat hypertension (high blood pressure). It was only approved for treating hair loss in men in 1988 as a topical medication. A women’s version was approved in 1991. To this day, it is not entirely clear as to how Minoxidil works in promoting hair growth, with a number of theories out there, implying the likely involvement of multiple mechanisms.
Oral Minoxidil for Hair Loss
For many years, I have heard that oral Minoxidil results in even more hair growth compared to the topical version. However, I always assumed that the side effects from oral Minoxidil would be much worse. Besides blood pressure fluctuations and potential water retention, I was most concerned about the side effect of excess body hair growth from oral Minoxidil turning me into a werewolf. Note: Make sure to read my post on topical Minoxidil and beard growth.
Dr. Pathomvanich: Ok for Select Patients
Several years ago I read and bookmarked a very lengthy and thoughtful comment by respected Thai hair transplant surgeon Dr. Damkerng Pathomvanich about why he prescribes oral Minoxidil to a select few of his patients. According to him as well as other physicians that had given him feedback, 5 mg per day was an ideal dosage that did not even change patient blood pressure readings significantly. However, some western publications and websites recommend a lower dosage (see links in some of the comments to this post). Image below shows generic 5 mg Minoxidil tablets from Thailand.
Side effects are still possible at low doses. Dr. Pathomvanich does not prescribe oral Minoxidil to patients who have blood pressure, heart, liver or kidney problems. Note that according to the official brochure for Loniten, maximum recommended dosage is listed as high as 100 mg per day, which seems crazy. Most patients taking the drug for hypertension do not cross 40 mg per day.
Dr. Sinclair Recommends Oral Minoxidil
I had forgotten about the above till today, when commentator “Billa” posted an interesting link to a new audio interview with Australian Dr. Rodney Sinclair. I have covered this well known hair expert a number of times on this blog in the past. In this latest interview, one of the things that Dr. Sinclair states is that oral Minoxidil is much more effective than topical Minoxidil when it comes to hair growth based on some clinical trials that his clinic is currently undertaking.
While the article describing the above interview states that side effects from oral Minoxidil were not significant according to Dr. Sinclair, I did not hear that in the audio interview. I am guessing that this must be true or else they would stop conducting the trials.
Note that oral Minoxidil is not currently FDA approved for treating hair loss, and I do not intend to take the drug.