Dutasteride Works when Finasteride Fails

In 2021, the single most important drug in the fight against hair loss remains Dutasteride (brand name Avodart). However, it is not approved for that use by the US FDA. I have written numerous past posts on Dutasteride to treat male pattern hair loss.

The most useful one remains my Avodart reviews for hair loss post due to the vast number of reader comments. Also see my posts on Dutasteride injections (also knows as mesotherapy).

Dutasteride v/s Finasteride Dosage and DHT Reduction
Dutasteride reduces more Dihydrotestosterone (DHT) than Finasteride.

Dutasteride more Potent than Finasteride

Every week I search PubMed for the latest papers on Dutasteride and hair loss. This week, I discovered an important new June 2021 study that was just published. It is titled:

“Change in hair growth-related gene expression profile in human
isolated hair follicles induced by 5-alpha reductase inhibitors: dutasteride and finasteride.”

The findings of this study are quite interesting and related to something similar that I published in 2014 (see old post at bottom). Note that this latest work was led by Japanese researchers and funded by GlaxoSmithKline (GSK), the manufacturer of Avodart.

It is encouraging to see GSK still interested in Avodart for hair loss. They will almost certainly not try to get the drug approved to treat hair loss in the US or EU. To date, Japan and South Korea remain the only countries where you can officially use Dutasteride to treat hair loss.

In the rest of the world, the drug is prescribed to treat enlarged prostates (BPH) in older men. For hair loss, you need off-label prescriptions. Also note that on average, side effects from Dutasteride are worse than from Finasteride.

Although GSK is headquartered in the UK, this particular research was affiliated with the company’s Singapore subsidiary. Professor Manabu Ohyama (who I have covered in the past) gave advice on the study protocol and methodology.

Key Findings

The key findings of this latest paper on Dutasteride (and Finasteride) include:

  • Dutasteride and Finasteride both suppressed the negative effects of testosterone on hair-related gene expression.
  • In particular, the gene expression for growth factors FGF7, IGF1 and WNT5a.
  • Dutasteride may have a stronger inhibitory potency to increase growth factor expression than Finasteride.
  • Dutasteride’s greater efficacy on hair growth in comparison to Finasteride is possibly due to the inhibition of 5α-reductase Type 1; or due to greater inhibition of 5α-reductase Type 2 by Dutasteride when compared to Finasteride. My note: most likely both issues are at play per next conclusion.
  • The authors claim that there results suggest that: “Type I 5 alpha reductase may play an important role in hair growth along with Type II 5 alpha reductase.

I forgot that this issue of the significance of Type 1 5α-reductase in relation to hair loss is still unresolved. My guess is that Type 1 is significant, but not quite as significant as Type 2. Dutasteride attacks both Type 1 and Type 2, while Finasteride only attacks the latter.

Make sure to also read my post on destroying androgen receptors on the scalp.

June 8, 2014

Dutasteride Works when Finasteride Fails

An interesting study by South Korean scientists was recently published in “The International Journal of Dermatology”.  It measured the effect of Dutasteride on men with androgenetic alopecia unresponsive to treatment with Finasteride.

They took 35 balding people who did not see any improvement while on Finasteride 1 mg/day for 6 months. They then put those same people on Dutasteride 0.5 mg/day for 6 months.  31 of those patients completed the 6 months of treatment.  Hopefully, the 4 who stopped treatment did not stop due to experiencing significant side effects.

Over three-quarters of these 31 patients saw at least some increase in hair count. Only 1 patient had a marked improvement, while 6 patients had a moderate improvement and 17 patients had a slight improvement. The remaining 7 patients did not see any improvement or worsening.

Side effects included transient sexual dysfunction in 6 patients (17.1%).

Are Obese Men Less Likely to go Bald?

Obesity and Hair Loss.
Are obese people less likely to have hair loss?

I think that obese men are slightly less likely to be bald than people of lower or normal weight. My guess for this is due to the favorable scalp hair growth effects of extra estrogen and lower testosterone in obese individuals.

When I wrote this post, I ran a poll and only 26 percent of people agreed with my hypothesis. Another 31 percent were unsure. The second half of this post is from 2017 and has those details. The first half is an update with new findings that contradict my hypothesis.

Update: June 25, 2021

Obesity and Increased Hair Loss

Earlier today, Dr. David Sinclair posted a link to an interesting new Japanese study titled: “Obesity accelerates hair thinning by stem cell-centric converging mechanisms.” Apparently, obesity-induced stress targets hair follicle stem cells (HFSCs) to accelerate hair thinning. Excess body fat induces stem cell inflammatory signals which accelerate the miniaturization of mini-organs and repress regeneration. Obesity also leads to marked inhibition of Sonic hedgehog (SHH) signaling.

Moreover, a 2014 study from Taiwan concluded that a higher body mass index (BMI) was associated with a greater severity of androgenetic alopecia (AGA). However, in this particular case, the findings only pertained to those who already suffered from AGA. There was no proof that obesity could actually spur the onset of hair loss.

Do note that obesity due to excessive food intake likely has different hormonal effects in comparison to obesity due to excessive alcohol intake. And obesity due to existing thyroid or pituitary gland related hormonal disorders is also very different.

Despite the above new Japanese study, I am still not convinced. The hormone altering modern diet and lifestyle is likely more of an issue in causing rising rates of balding around the world. Rather than just actual weight gain. But my opinion and guessing does not mean much of course.

High Body Mass Index and Better Hair?

May 13, 2017

Last week, a new study from Germany concluded that short men are more likely to go bald prematurely (i.e., at an earlier age). This was very surprising to me, since I never noticed any strong correlation between height and scalp hair quantity in real life. The same study also alluded to the fact that “white men in particular lose their hair prematurely”. Something I have also observed and mentioned on this blog before. The above study was widely covered by the global media.

On the other hand, one correlation that I have definitely noticed is that men who are obese seem to on average have a at least modestly lesser chance of balding in comparison to: men who are of average weight; or are slightly overweight; or are slightly underweight. For the sake of simplicity, assume that the definition of an obese man (of average height) is someone who is at least 50 lbs overweight.

On hair loss forums, people often talk about changing their diet to a healthier one in order to see if it improves scalp hair. However, if anything, I have seen highly obese people with a terrible junk food and soda filled diet having better hair than those with more regular diets. I hope I am wrong about that observation.

Moreover, when people lose a lot of weight, one frequent complaint seems to be the side effect of hair loss. This might be a temporary shedding (telogen effluvium) problem in most cases.

Obesity’s Impact on Testosterone and Estrogen

If the above inverse correlation between weight and scalp hair quantity is true, the main reason is probably because very fat men tend to have lower levels of testosterone. This would mean they most likely also have lower levels of dihydrotesterone (DHT), the main culprit in male pattern hair loss. An important study from 2008 found that higher waist circumferences were associated with lower testosterone levels.

It seems like obese men might also have higher estrogen levels, which can benefit scalp hair significantly. See my post on estrogen and hair growth.

Update: I had to delete the poll in 2018 due to some plugin issues. The results of the poll are summarized below.

In your daily life, have you noticed that obese men are less likely to go bald in comparison to non-obese men?

Total responses = 1,380.

Yes = 362 (26.2%).

No = 595 (43.1%).

Not Sure = 423 (30.7%).