Hair Restoration Blog

Here at US Hair Restoration, we are constantly hearing about the concerns of our many patients who have been prescribed the popular hair loss preventative medication known as Propecia (finasteride). Most patients with concerns have seen recent news reports, commercials, or magazine ads talking about the dangers of taking Finasteride. Since this is an effective medication proven to aid in the sustainment of receding or thinning hair, it is important to explain the facts in comparison with the rumors.

Early side effects (1 year)

The reported side effects based off of precise medical research for Finasteride at the 1-mg dose are uncommon and reversible. The one- year drug related side effects were over 1% greater than in the control group. The data showed that 3.8% of men taking Finasteride 1mg experienced some form of sexual dysfunction verses 2.1% in men treated with a placebo.

Most reported rumors center around sexual dysfunction occurring after beginning use of the medication, but there have been reports of sexual dysfunction that have occurred at later points in time. When studies were performed based through proper research methods, the sexual side effects were reversed by all the men who discontinued therapy, and in 58% of those who continued treatment. Once the medication was stopped, side effects generally disappeared within only a few weeks.

The initial studies done on finasteride for 12 months show that 1.4% of patients taking Propecia (945 patients) were discontinued due to adverse experiences which may have been drug related.

Here is the break down on the sexual side effect of finasteride in the patients who used it for one year only.

The men who continued using finasteride resolved some of the side effects in many cases. The resolution of the side effects was compared in the drug and placebo group. The incidence of each of the above adverse experiences decreased to ≤0.3% by the fifth year of treatment with Propecia.  This shows improvement of the side effects in the patients who took it over time.

In a study of finasteride 1 mg every day in men showed some decrease in volume to ejaculate of 0.3 mL (-11%) compared with 0.2 mL (–8%) for placebo in 48 weeks after beginning the treatment. Decrease in ejaculate was shown more significantly in higher doses (5mg) of finasteride which is approximately 0.5 mL (-25%) compared to placebo in ejaculate volume.  However, the decrease in ejaculate has been seen to be reversible after the treatment has been stopped.

In the clinical studies with Propecia, the incidences for breast tenderness and enlargement, hypersensitivity reactions, and testicular pain in finasteride-treated patients were not different from those in patients treated with placebo.

Long term side effects (up to 4 years)

Long term side effects of Finasteride were extensively studied in the Finasteride 5mg (Proscar) Long-Term Efficacy and Safety Study for 4 years in 3040 patients (1524 on Finasteride 5 mg/day and 1516 on placebo). 3.7% (57 patients) treated with finasteride 5 mg and 2.1% (32 patients) treated with placebo discontinued therapy as a result of adverse reactions related to sexual function, which are the most frequently reported adverse reactions.

Although the initial side effects of Finasteride has been higher than placebo over time the difference decreases to the point that in years 2-4 of this research, no significant difference between the two groups (treatment groups and placebo) was reported in terms of the incidences of impotence, decreased libido and ejaculation disorder.

The new study published in the Science Translational Medicine Journal has shown there is an association of prostaglandin pathways in hair growth.  The study was done at the University of Pennsylvania and was published in March 2012 by Catseralis et. al. which reveals a new pathway for balding.  This has the potential to be a revolution in the treatment of hair loss in the most common type known as male pattern balding (see link).  Dr. Catseralis and his lab team at the University of Pennsylvania are known for their work on hair growth and its association with wound healing.  They have done similar research to what we performed at Johns Hopkins on wound healing and hair growth.  Their work on discovery of wnt-pathway has proved a link between wound healing and hair growth and has been one of the milestones in the field of hair restoration.  His other work was published in Nature Journal in 2007 (see link).

The authors review the main cause of male hair loss as testosterone.  Although the authors announce that the real mechanism of androgens on male patterned baldness is not clear, they try to go deeper and find the main mechanism of male patterned baldness at the molecular level. The study shows that the enzyme prostaglandin D2 synthase (PTGDS) is elevated at both the mRNA and protein levels in men with typical men hair loss (AGA). It is also documented that the product of PTGDS enzyme activity or prostaglandin D(2) (PGD2), is elevated in scalp skin. The animal studies show that during normal follicle cycling in mice, the levels of those prostaglandins increase, suggesting an inhibitory effect on hair growth.

They showed that applied prostaglandin (PGD2) minimizes hair growth in human hair follicles that are planted in mice. Hair growth inhibition requires the PGD(2) receptor G protein, but not the PGD(2) receptor 1 (PTGDR).

These scientists have proven that prostaglandin in the mouse skin is associated with development of men hair loss, hair miniaturization, and scalp oil gland enlargement which are all hallmarks of male patterned hair loss. The study is especially significant because it introduces prostaglandins as a main player in inhibition of hair growth in male patterned hair loss. It suggests the prostaglandin related pathway as a potential target for treatment of common hair loss in men.

Hair stem cell research is one of the most promising areas for hair restoration in the future.  Currently there are many advanced techniques for hair transplantation; however a long journey remains in order to provide hair loss sufferers with an unlimited source of hair, and stem cells might be an answer to this need.  In the past we have reported in our blogs of the newest advances in hair restoration through stem cell research from our own research and that of other centers.

A new article published in the Journal of Dermatology Science in February of 2012 sheds fresh light on the subject.   Authors, Dr. Chen and Dr. Chuong from Taiwan reported on the type of environment hair stem cells require in order to produce new hair.  Hair Stem cell circulation has been thought to be regulated by signals from the micro-environment which is close to them in skin tissue named the “stem cell niche”.

The authors proposed recent studies which reveal that there can be multiple layers of environmental controls. These environmental controls were reviewed using the paradigm of hair stem cells. This is because in order to properly observe and analyze hair growth, it is easier to see their regeneration pattern characteristic that occurs on a regular basis in different phases.

The duration of hair growth determines the actual length of hair fibers. We now know the generation of a new anagen hair is a result of the interaction between the two different stem cells in each hair follicle.  Hair stem cells located in the bulge of the follicle interact with signals from the dermal papilla to produce a new hair.

The activation of hair stem cells has been shown to be modulated by molecules secreted from the intra-dermal fatty tissue as well as other hormonal signals, immune reactions, neural activities, and the aging process. The general physiological status of individuals is further influenced by cyclic rhythms and changing growth periods. The interactive networks of these environmental factors provide new understanding on how stem cell homeostasis is regulated.

The authors also discuss the environments which are involved in order to make new hair.  My hope is that as we become more aware of the circumstances involved in hair growth and development, we can develop more practical ways to use advanced stem cell technology for hair restoration.  The optimal solution for hair restoration might not be through the multiplication of hair stem cells, however increased knowledge on the environment which hair follicles grow can lead to procedures that reactivate the existing hair stem cells that are progressing toward miniaturization and eventual baldness.  Many physicians believe balding does not permanently affect hair follicles; rather the bald follicles keep their potential to be reactivated and grow healthy hair. This is of course, as long as the right environment is provided for the hair follicles to grow.

Q:

Hi Dr. Mohebi,

I am not sure how rare hair growth after wound healing is in humans, but having done my Master’s in Tissue Engineering I was excited to find out that my condition might be of benefit to science.

I recently lacerated my shin mountain biking and after it healed I have fast growing dark hair around it.  I don’t have much hair on my legs so it was quite a shock.

Anyway, I just thought I would send you an email in case this was important.  Perhaps its more common than the literature states.

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A:

Dr. Mohebi's research on wound healing and hair growth in animal model: Left: right after skin irritation, Right: 42 days after wound healing with longer than normal and de-pigmented hair

This is a great observation you’ve made.  The research team I was on had done some research on animal models a few years ago at Johns Hopkins that showed wound healing can enhance the growth of hair.  That was an incidental finding during some of our wound healing studies.  We noted some gene therapy techniques we used in the process of wound healing might have affected the hair in the animals we were studying.  In order to understand what this exact mechanism was, we did another study and only focused on hair growth.  It was during this particular study we noticed only the wounding of skin can cause hair to grow faster and thicker.

Before we publish our finding in our animal model of wound healing/ hair growth study, Dr. Cotsarelis and his team from the University of Pennsylvania published a very nice article in Nature in 2007: “Wnt-dependent de novo hair follicle regeneration in adult mouse skin after wounding”

This study has never been duplicated in humans, but it is a subject that definitely requires more investigation.  It is possible that with the same mechanism, the wound healing process in humans can affect hair growth.  We do know this won’t happen every time we have an injury in our body.  However, I am interested to know what other elements were happening in your case. Whether you had any medical condition, used medications during the time of injury or after, and how your wound was treated?  I also would like to see some pictures of the area with growing hair!