Dht & (topical) Finasteride, A Bit Confused, Need Explanation

[alibaba92]

Hi guys,

Sorry for asking basic stupid question here, but it bugs my mind so I have to ask:

1. Is DHT produced directly on-site, where it is needed ? OR is it all produced in one place in our body and then transported/conveyed to places where it is needed ? I assumed the first happened, is it correct ?

2. Finasteride blocks 5AR type 2 => serum DHT reduces => tissue DHT (in the scalp) reduces => shedding stops. BUT BUT BUT, scalp 5AR is type 1, so, DHT will still be produced in the scalp and fck our hair. So, why does finasteride work ? The key is to reduce tissue DHT in the scalp, not serum DHT, right ? When serum DHT reduces, scalp DHT will still be produced because 5AR type 1 is still there, right ?

3. Similarly, for topical finasteride, it will block 5AR in the scalp, but type 2, not type 1, BUT BUT BUT type 1 is the one that is present in our scalp, so, does it mean that topical finasteride will not work, theoretically ?

4. I saw so many horror stories regarding insane shedding, is it “Telogen Effluvium” caused by hormone imbalance after taking finasteride (after taking finasteride, T will be up, and then, Testosterone : Estrogen ratio shoot up => Telogen Effluvium => crazy shedding) ?

 

[Retinoid]

1) DHT is a tissue specific hormone and is converted at the tissue level. While there is serum DHT it only acts on the tissue it is made in (such as prostate, hair follicle, etc.) unlike things like Testosterone and Estrogen which are made in specific areas but then go off to act on various places in the body. Serum DHT is basically a spill over from DHT being made in the tissues.

2) While Finasteride clinically only blocks 5AR2 and 3, 5AR1 is left untouched for the most part. 5AR1 does not seem to have a significant role in hair loss. While present in the scalp, the hair follicle has 5AR2 which is what seems to be the cause of baldness. Merck for example tested a 5AR1 inhibitor and it was barely more effective than the placebo. Also the pseduohermaphrodites that never get baldness are lacking 5AR2, but have normal 5AR1 and 3.

3) See above

4) Anytime you start a treatment for hair, it could cause a disruption in hair cycles so there can be a shed. The Telogen Effluvium in Finasteride should not be as bad as Minoxidil nor is it extremely common for a Telogen Effluvium to occur with Finasteride.

 

[alibaba92]

1) DHT is a tissue specific hormone and is converted at the tissue level. While there is serum DHT it only acts on the tissue it is made in (such as prostate, hair follicle, etc.) unlike things like Testosterone and Estrogen which are made in specific areas but then go off to act on various places in the body. Serum DHT is basically a spill over from DHT being made in the tissues.

2) While Finasteride clinically only blocks 5AR2 and 3, 5AR1 is left untouched for the most part. 5AR1 does not seem to have a significant role in hair loss. While present in the scalp, the hair follicle has 5AR2 which is what seems to be the cause of baldness. Merck for example tested a 5AR1 inhibitor and it was barely more effective than the placebo. Also the pseduohermaphrodites that never get baldness are lacking 5AR2, but have normal 5AR1 and 3.

3) See above

4) Anytime you start a treatment for hair, it could cause a disruption in hair cycles so there can be a shed. The Telogen Effluvium in Finasteride should not be as bad as Minoxidil nor is it extremely common for a Telogen Effluvium to occur with Finasteride.

Thanks for the answer

2) I thought hair follicle only has 5ar type 1 but none of 5ar type 2.

4) Why there should be discruption in the 1st place ? Cause didnt we just reduce tissue DHT in the scalp then it should not affect right ?

 

[Nostro100]

DHT biosyntheses from wikipedia. https://en.wikipedia.org/wiki/Dihydrotestosterone#Biosynthesis
"SRD5A1 is most highly expressed in non-genital skin/hair follicles, the liver, and certain brain areas, while lower levels are present in the prostate, epididymides, seminal vesicles, genital skin, testes, adrenal glands, and kidneys.[8] In the skin, 5α-reductase is expressed in sebaceous glands, sweat glands, epidermal cells, and hair follicles.[57][58] Both isoenzymes are expressed in scalp hair follicles,[59] although SRD5A2 predominates in these cells."


PS; (SRD5A1) = 5AR1 ... and so foward...

 

[Nostro100]

Thanks for the answer

2) I thought hair follicle only has 5ar type 1 but none of 5ar type 2.

4) Why there should be discruption in the 1st place ? Cause didnt we just reduce tissue DHT in the scalp then it should not affect right ?

Yup... That's what I think it's missing in a lot of studies. IF people trying Topical finasteride and Dutasteride show good results and lower side effects, it just comes to prove that it's easier to disrupt the production of DHT locally than to do it systemically (oral)