Mechanism of finasteride side effects

luke77

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Hi everyone,
I'm just wondering HOW finasteride causessexualside effects...I've read that it increases testosterone levels, which would imply stronger sexual function, but it must decrease something else as well. Is dht involved in sexual function, and that is why it causes sexual side effects sometimes? Or is it something totally different?

Thanks,
Luke
 

HairlossTalk

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Inhibition of the formation of DHT results in extra Free Testosterone in the blood. This results in the preliminary increased libido, oily face, slight acne, oily eyebrows, etc reported by users. Body takes care of the excess Testosterone and you go into a dry spell which accounts for the low libido, dry skin, etc. Eventually body reaches a stable equilibrium (assuming you're not being an armchair chemist and double dosing or skipping every 3rd day or some other weird concept) ... and side effects subside. This is why one should try Propecia for at least a month or two before deciding whether side effects will be a problem long term or not.

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luke77

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Thanks, this is what I was looking for. A quick follow up question - when you say that the body "takes care" of the extra testosterone that comes about after starting finasteride, do you mean that the body stops producing as much testosterone because it senses the increase that comes with the finasteride? If so that's good news for me because my body has stopped producing test. and I'm getting injections...so theoretically, does this mean that I would have no risk of sexual side effects?

Thanks again,
Luke
 

hairschmair

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My theory on finasteride libido side-effects.

Theory:

Some people's endocrin system permanently raise their level of Testosterone when DHT levels are down. The added Test counteracts the lowered DHT when it comes to libido.

Those that experience a huge libido drop are the ones who do not experience a rise in Testosterone to go with it.

Pure congesture of course. We'd need blood tests before/after for a group of people who do and don't experience these side-effects to find out.

Any experts' thoughts?
 

hairschmair

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Alternatively, each person draws their 'mojo' from a different distribution of DHT/Testosterone. i.e. some people really need their DHT and others don't.
 

global

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luke77 said:
Hi everyone,
I'm just wondering HOW finasteride causessexualside effects...I've read that it increases testosterone levels, which would imply stronger sexual function, but it must decrease something else as well. Is dht involved in sexual function, and that is why it causes sexual side effects sometimes? Or is it something totally different?

Thanks,
Luke

Yes DHT is an androgen itself ( I believe stronger than testosterone) so the drop in DHT may not be compensated for even with a permanent rise in test levels.
 

chewbaca

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After permanent rise in Testes level, if u stop DHT inhibition through propecia, will the hair loss get more severe a there is so much Testes floating about and naturally more of it will be converted to DHT?
 

HairlossTalk

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luke77 said:
when you say that the body "takes care" of the extra testosterone that comes about after starting finasteride, do you mean that the body stops producing as much testosterone because it senses the increase that comes with the finasteride?
No. My understanding is that it converts it to estrogen. Excess T gets converted to E. This is why some guys have gyno problems (very rare). And Yes. Eventually equilibrium is reached again because the body figures out what is going on and overcompensates and undercompensates production of the various hormones.

HairLossTalk.com
 

Dave001

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luke77 said:
Hi everyone,
I'm just wondering HOW finasteride causessexualside effects...I've read that it increases testosterone levels, which would imply stronger sexual function, but it must decrease something else as well. Is dht involved in sexual function, and that is why it causes sexual side effects sometimes? Or is it something totally different?

Sexual functioning is influenced by androgens, among which both testosterone and dihydrotestosterone (DHT) are included. DHT has a greater binding affinity for the androgen receptor than testosterone; i.e, it's a more "powerful" androgen.

The wood-inhibiting property of finasteride is a direct consequence of its interference with the metabolism of testosterone to its more potent metabolite, DHT. The conversion is mediated by the enzyme 5a-reductase (5aR), which is inhibited by finasteride. Although the mechanism of 5aR inhibitors is different from antiandrogens, the net effect is the same: fewer androgen receptors are activated.

The reason that finasteride produces fewer side-effects than classical antiandrogens (at a comparable clinical effect) is that androgen activity is selectively reduced in tissues where 5aR is present, such as the hair follicle, prostate, brain, and genitalia. The spillover effect from circulating androgens is probably relatively small. There is also an upper limit imposed on the degree to which androgen activity can be reduced by 5aR inhibitors, because other androgens (e.g., testosterone) aren't prevented from activating the androgen receptor, whereas antiandrogens prevent any androgen from binding to the androgen receptor.

Once you have a reasonable understanding of androgen metabolism and 5aR distribution in various tissues, the idea of using systemic 5aR inhibitors such as finasteride will become much less attractive.

If peak mental and physical performance is of importance to you, you'd be much better served by a topical antiandrogen such as spironolactone.
 

Dave001

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HairlossTalk said:
luke77 said:
when you say that the body "takes care" of the extra testosterone that comes about after starting finasteride, do you mean that the body stops producing as much testosterone because it senses the increase that comes with the finasteride?
No. My understanding is that it converts it to estrogen. Excess T gets converted to E. This is why some guys have gyno problems (very rare). And Yes. Eventually equilibrium is reached again because the body figures out what is going on and overcompensates and undercompensates production of the various hormones.

DHT itself is antiestrogenic, which is probably the most important factor in explaining estrogenic related side-effects.
 

Bismarck

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I have to correct you guys a bit.

Natural estrogens in physiological doses do actually increase the libido via ß-endorphine. Finasteride -by inhibiting 5ar activity- causes a tailback of DHEA which eventually finds it's way over 17ß-HSD to androstendiole. Androstentiole immediately attaches to the estrogen receptors and is metabolized via testosterone (circumventing free endoplasmatic 5ar) to E2 (=> gyno).


bis
 

hairschmair

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Dave001 said:
If peak mental and physical performance is of importance to you, you'd be much better served by a topical antiandrogen such as spironolactone.

Theory is all well and good but it doesn't explain how after 6 months of finasteride I have seen no effect on my libido, mental or physical performance.
 

global

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Bismarck said:
I have to correct you guys a bit.

Natural estrogens in physiological doses do actually increase the libido via ß-endorphine. Finasteride -by inhibiting 5ar activity- causes a tailback of DHEA which eventually finds it's way over 17ß-HSD to androstendiole. Androstentiole immediately attaches to the estrogen receptors and is metabolized via testosterone (circumventing free endoplasmatic 5ar) to E2 (=> gyno).


bis

In laymans terms?
 

Dave001

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Bismarck said:
I have to correct you guys a bit.

How about quoting the text that you're "correcting"?

Natural estrogens in physiological doses do actually increase the libido via ß-endorphine. Finasteride -by inhibiting 5ar activity- causes a tailback of

Whoa, hold on. What the hell is a tailback? Since we're not talking talking about football (American), I'm guessing you mean a pileup, for which accumulation, or any number of synonymous words in the dictionary would much better substitute.

DHEA which eventually finds it's way over 17ß-HSD to androstendiole. Androstentiole immediately attaches to the estrogen receptors and is metabolized via testosterone (circumventing free endoplasmatic 5ar) to E2 (=> gyno).

Do you have any references to support this outlandish claim?

Estrogen is important for maintaining libido in both sexes, but that doesn't contradict what anyone else has said in this thread. Kevin mentioned estrogen specifically in connection with gyno, not libido.
 

Dave001

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hairschmair said:
Dave001 said:
If peak mental and physical performance is of importance to you, you'd be much better served by a topical antiandrogen such as spironolactone.

Theory is all well and good but it doesn't explain how after 6 months of finasteride I have seen no effect on my libido, mental or physical performance.

What "theory" are you referring to? Whether or not the effect is severe enough to be noticed subjectively is not an issue that was addressed by my comment.
 

Bismarck

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Tailback: You're right, I'm not a native English speaker .. but you got my point obviously.

I was mainly referring to the statement that "excess T gets converted to E". Go to a well equipped library to verify these outlandish claims.
:wink:
 

HairlossTalk

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Learn something new every day!

Althought I must admit I am still trying to figure out what some of you have said, so I will pick everything apart and hopefully you will both respond in the most "dumbed down" terms possible:

Sexual functioning is influenced by androgens
For the users, what exactly *is* an androgen? My half tongue in cheek guess is that its similar to a nerve. Maybe a little dangly thing that, when activated, transmits erotic sensations resulting in what we call libido. :)

The wood-inhibiting property of finasteride is a direct consequence of its interference with the metabolism of testosterone to its more potent metabolite, DHT.
It was an interesting sensation to go on Finasteride. As Bryan knows, I was an extremely hypersensitive responder to everything it did in my body. I could tell you without a minute of study in a library, exactly what tissues had 5-ar present, as their sensitivity and function changed very noticeably. I could have marked them with a crayola marker on my skin. Additionally, the difference in the "sweetness" of the libido I felt prior to Propecia (when it was dominated by the more potent DHT)... to the way sex drive felt while ON propecia and experiencing a testosterone (versus DHT) jolt .... to the way sex drive felt after I discontinued Propecia (again being run by the more potent DHT) ... was extremely noticeable. I remember making a mental note of how it actually felt "Different". Still there. Still true. But somehow ... less "sweet" for lack of a better term.

The reason that finasteride produces fewer side-effects than classical antiandrogens (at a comparable clinical effect) is that androgen activity is selectively reduced in tissues where 5aR is present
Translation: Finasteride only affects certain parts of the body, whereas an "Antiandrogen" globally affects all androgen containing tissues.

The spillover effect from circulating androgens is probably relatively small.
Please clarify this. Assumption: You're saying that the effect from the resulting increase in free Testosterone is not usually too noticeable. You probably wont see much increase in libido from that time period soon after starting finasteride when testosterone increases. Yes?

There is an upper limit... androgen activity can be reduced by 5aR inhibitors, because other androgens (e.g., testosterone) aren't prevented from activating the androgen receptor
"androgen activity" again in this case means effect on libido? Meaning, though ye inhibit DHT, thine Testosterone may still arouse Thee?

Once you have a reasonable understanding of androgen metabolism and 5aR distribution in various tissues, the idea of using systemic 5aR inhibitors such as finasteride will become much less attractive.
Amen to that one. Put another way, you're basically pouring paint into an Olympic Sized pool when all you really wanted to do was give a few tiles some color.

If peak mental and physical performance is of importance to you, you'd be much better served by a topical antiandrogen such as spironolactone.
On a scale of 1 to 100 ..... 1 being ineffective and 100 being completely effective .... and for the sake of argument Propecia being ... say ... 83 on that scale :lol: .... honestly where would you rate the effectiveness of topical spironolactone 5% lotion in actually working?

Theory is all well and good but it doesn't explain how after 6 months of finasteride I have seen no effect on my libido, mental or physical performance.
Is it correct to say that sensitivity, awareness, and even possibly tissue distribution of androgen receptors that are compatible with DHT may differ from person to person? The theory has been raised that some guys live a life of libido powered by testosterone versus DHT ....

Natural estrogens in physiological doses do actually increase the libido
Translation for the tards (of which I am one) ... This means naturally produced estrogen in your body does contribute to libido. That "Physiological doses" thing threw me for a minute there :)

DHT itself is antiestrogenic, which is probably the most important factor in explaining estrogenic related side-effects.
Please rephrase this. This, rephrased, will answer the initial guy's question in the first post, and simultaneously correct any misinformation I may have spewed. My statement was excess T gets converted to E in the brain, liver, etc. Clearly I was wrong. Your answer to his question then is "DHT is an anti-estrogen". What does DHT do that reduces estrogen? Does it then follow that lack of DHT formation equals increased ability for estrogen to form and "pile up" ?

DHEA which eventually finds it's way over 17ß-HSD to androstendiole. Androstentiole immediately attaches to the estrogen receptors and is metabolized via testosterone (circumventing free endoplasmatic 5ar) to E2 (=> gyno). <----- Do you have any references to support this outlandish claim?
Id like you two to resolve this so I can know what the hell is being disagreed on here :)

Estrogen is important for maintaining libido in both sexes, but that doesn't contradict what anyone else has said in this thread. Kevin mentioned estrogen specifically in connection with gyno, not libido.
I was mainly referring to the statement that "excess T gets converted to E". Go to a well equipped library to verify these outlandish claims.
Wait, so I was right, or I was wrong? Since this question gets asked at least 43 times a day, I need to know the accurate response.

HairLossTalk.com
 

Bismarck

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Quote:
Sexual functioning is influenced by androgens

For the users, what exactly *is* an androgen? My half tongue in cheek guess is that its similar to a nerve. Maybe a little dangly thing that, when activated, transmits erotic sensations resulting in what we call libido.

Androgens are steroid hormones that regulate masculine characteristics by binding to androgen receptors. That's an appropriate definition I'd say.
 

Bismarck

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[quote:bef20]If peak mental and physical performance is of importance to you, you'd be much better served by a topical antiandrogen such as spironolactone.

On a scale of 1 to 100 ..... 1 being ineffective and 100 being completely effective .... and for the sake of argument Propecia being ... say ... 83 on that scale Laughing .... honestly where would you rate the effectiveness of topical spironolactone 5% lotion in actually working? [/quote:bef20]

Now, that's a good point. I'd give it 30.
 

HairlossTalk

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Sorry I meant to ask what exactly is an androgen *receptor*.
 
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