Category Archives: PGF2a

Increasing PGE2 and PGF2a for Hair Growth

In a number of past posts, I have discussed how hair loss is impacted by prostaglandins (lipids). Most of my focus has been on how a reduction in prostaglandin D2 (PGD2) levels benefits hair growth. In this post, I will discuss how an increase in levels of prostaglandin E2 (PGE2) and PGF2a (PGF2α) leads to hair growth.

PGE2, PGF2a and Hair Growth.
Increase PGE2 and PGF2a for hair growth. Reduce PGD2.

It has also been hypothesized that the balance between PGE2 and PGD2 levels controls hair growth. Increased levels of PGD2 and reduced levels of PGE2 have been observed in the scalps of men suffering from androgenetic alopecia (AGA). Also of note, PGE2 is known to act synergistically with PGF2 alpha

PGE2 and Hair Growth

PGE2 (also known as dinoprostone) is a naturally occurring prostaglandin that is also known to interact with Wnt signaling. A number of studies have shown that increasing PGE2 levels on the scalp can benefit hair growth.

An interesting 2019 study found that one of the ways in which skin and tissue injury can sometimes lead to hair growth is via an increase in PGE2.

A 2018 case report from Spain found that the drug Omeprazole induced hypertrichosis (excessive body hair) in two children. This side effect resulted from a significant increase in prostaglandin E2 levels. Once Omeprazole therapy was stopped, the excess body hair entirely disappeared after six months.

One of the ways in which Minoxidil works to grow hair is via increasing PGE2 levels.

Dexamethasone and Sulfasalazine can both increase prostaglandin E2 levels significantly.

Natural products such as castor oil are thought to raise PGE2 levels, and potentially benefit hair growth. Even if true, such gains will be modest at best in my opinion.

PGF2α (aka PGF2a) and Hair

PGF2α acts by binding to the prostaglandin F2α receptor. When injected into the body or amniotic sac, PGF2α can either induce labor or cause an abortion in a pregnant woman. PGF2a levels are higher in people with non-balding scalps.

In the past, I have written in detail about the glaucoma drug Bimatoprost. This drug is an analog of prostamide F2a, which is almost the same as prostaglandin F2a. Bimatoprost raises both PGF2a and PGE2 levels, and is therefore the key ingredient in eyelash hair growth drug Latisse.

Another analogue of prostaglandin F2a is the well known drug Latanaprost. It prolongs the anagen phase of the hair cycle via the prostaglandin effect.

Another glaucoma and high eye pressure relief drug named Travoprost has a patent related to its scalp hair growth properties. Travaprost raises both PGF2α and PGE2 levels on the scalp when applied topically.

The only other major PGF2a analogue pharmaceutical on the market is called Carboprost.

Bimatoprost and Hair Loss

It is 2015, and therefore finally a good time to write about Bimatoprost. The main reason for this is that at the end of January 2015, Allergan’s phase II clinical trials for the use of Bimatoprost for hair loss in humans are ending. It is expected that results will be announced shortly thereafter.

What is Bimatoprost?

Bimatoprost is a synthetic prostamide (= prostaglandin-ethanolamide) analog. Bimatoprost is sometimes mistakenly called a prostaglandin analog, since prostaglandins and prostamides are structurally similar to each other. Bimatoprost is increasingly being used in dermatological applications, including for hair loss and pigment related skin issues.

Prostaglandins were originally named due to the mistaken assumption that they were derived from the prostate gland and its secretions. I have written a number of posts on this blog regarding prostaglandin D2 (PGD2) and prostaglandin E2 (PGE2). PGD2 is especially important when it comes to hair loss. Bimatoprost is a prostamide F2α analog. Latanoprost and Travoprost are examples of prostaglandin F2α analogs.

Current Uses

While approval for use to grow scalp hair will depend on the upcoming phase 2 clinical trial results (and hopefully Allergan will decide to fund further phase 3 clinical trials), Bimatoprost has already been FDA approved for use in humans for:

  1. Glaucoma and ocular hypertension treatment, approval in 2001 (brand name Lumigan). Dosage = 1 drop of Lumigan 0.01 percent or Lumigan 0.03 percent depending on source, once daily.
  2. Eyelash growth (lengthening) treatment, approval in 2008 (brand name Latisse). Dosage = 1 drop of Latisse 0.03 percent, once daily.

Bimatoprost Side Effects

Although there are some significant side effects (e.g., darkening of iris, undereye, eyelash and eyelid), that can occur when using Bimatoprost for the above applications, most seem to be reversible. It is also great to know that people have been using this product in such a sensitive areas as the eye for over a decade now without any large-scale reports of major injuries, nor any class action lawsuits against Allergan.

Will Bimatoprost be a Miracle Treatment for Hair Loss?

Initially when I first read about Bimatoprost a few years ago, I felt that it was going to be inferior to Minoxidil and not worth researching. For one, eyelash growth type results on scalp hair would be a joke in my opinion. More significantly, I thought that all Bimatoprost was doing was keeping scalp hair in anagen (growth) phase for a longer duration, and once the androgens/ dihydrotestosterone (DHT) killed the scalp hair, Bimatoprost would no longer have any positive effect. So my feeling was that all you were getting was a temporary spike in the amount of your hair that was in anagen phase, and a temporary spike in the length of your scalp hair.

However, I have started to doubt my initial skepticism about this. In 2013 Dr. Valerie Randall and a number of other co-authors published a great study on the successful use of Bimatoprost to grow human hair (in organ culture) and mouse hair (in vivo). The most interesting aspect of the study was that it seems like Bimatoprost stimulates intercellular signaling pathways and causes keratinocytes to produce increased hair growth as well as melanocytes to produce increased pigmentation. The whole process seems to start in the dermal papilla (which ties in to my recent posts on the University of Calgary’s and Replicel’s work related to dermal sheath cup cells).

It seems like Bimatoprost is not just temporarily keeping scalp hair in anagen phase longer. It is actually altering scalp biology at the cellular level and changing paracrine signaling (cell to cell communication) that may end up increasing protection against the ravages of DHT. According to the study:

Bimatoprost caused individual isolated scalp hair follicles from 10 different people to stay in anagen longer in organ culture, and about one-third more new hair was synthesized over 9 d with 100 and 1000 nM.

Note that the 100nM and 1000nM are dose measures, and much higher than the 0.03% present in Latisse and Lumigan. Another part of the study concludes that results from 100nM were better than from 10nM, but results from 1000nM were essentially the same as from 100nM. This is kind of the same phenomenon that we see in studies that show the negligible gains from higher and higher doses of Finasteride or Dutasteride.

My feeling is that Bimatoprost may result in slightly superior results to Minoxidil, but nothing extraordinary. Will this be sufficient for Allergan to fund final stage 3 clinical trials?  I would hope so, considering how well the company has done recently (stock price has almost doubled in the past year), although I wonder if the company’s November 2014 acquisition by Ireland-based Actavis might lead to some delays in the decision making process?