Need Help Understanding Testosterone Levels & Propecia's Effect

[Donny J]

I stopped taking propecia on April 28th. I don't have my Testosterone/Free-T or DHT levels prior to quitting, but on June 10th (6 weeks off), they were as follows:

T: 522 ng/dL
Free-T: 18 ng/dL
DHT: 434 pg/mL


I've been considering re-starting propecia, but this time taking it EOD. So, I went and got my tests done again (now 10 weeks off), and I'm surprised to see that everything has pretty drastically decreased:

T: 311 ng/dL
Free-T: 9.6 ng/dL
DHT: 301 pg/mL


Can someone help me understand this? I'm obviously confused why my DHT levels would drop, but I'm also trying to understand what finasteride does to Testosterone levels -- doesn't propecia typically decrease T levels as well? Or do I have this backwards?

I should also note that since 6/10, I've been working out 5+ days a week and I feel that my libido has greatly increased.

 

[xRedStaRx]

Finasteride increases T levels, and potentially free T as well.

You were off them at both tests, so you didn't really control for finasteride here.

Besides, hormones fluctuate wildly throughout the day, week, month, and even seasons. Taking two tests a week apart and averaging them would be better. And do it fasted in the morning with no dinner before bed, get enough sleep, and no intense workouts two days before testing.

 

[zzzzz]

Finasteride won't lower your T levels it will raise them. Everything redstar said is correct. For the second test finasteride wasn't even in your system anymore and those are you normal levels (uninfluenced by finasteride)

 

[Donny J]

Finasteride increases T levels, and potentially free T as well.

You were off them at both tests, so you didn't really control for finasteride here.

Besides, hormones fluctuate wildly throughout the day, week, month, and even seasons. Taking two tests a week apart and averaging them would be better. And do it fasted in the morning with no dinner before bed, get enough sleep, and no intense workouts two days before testing.

Finasteride won't lower your T levels it will raise them. Everything redstar said is correct. For the second test finasteride wasn't even in your system anymore and those are you normal levels (uninfluenced by finasteride)

appreciate the info... a couple follow-up questions:

-if finasteride increases your T levels, then wouldn't your libido increase when on finasteride? most people have the opposite effect...unless there's not a direct correlation between T and libido like i'm thinking there is?

-what's the correlation between T and DHT then? i.e., is DHT formed as a counterpart to T? or is there no connection between the two and they're formed independent from one another?

 

[xRedStaRx]

appreciate the info... a couple follow-up questions:

-if finasteride increases your T levels, then wouldn't your libido increase when on finasteride? most people have the opposite effect...unless there's not a direct correlation between T and libido like i'm thinking there is?

-what's the correlation between T and DHT then? i.e., is DHT formed as a counterpart to T? or is there no connection between the two and they're formed independent from one another?

I'm in a rush so I can't give detailed explanations.

- The increase is very subtle and should not have an effect on libido. Besides, there is a very low threshold level of testosterone on libido.

- DHT is a metabolite of T. It's a stronger version of T. The 5-AR enzymes take a free T molecule and remove a double bond, adding 2 hydrogen atoms to it's composition. Essentially making it a more powerful version of testosterone by increasing their affinity towards androgen receptors, as well as inducing stronger androgen signals. But a biochemist should expand on the latter further as it is not my topic of competence.

 

[californiaoceans911]

appreciate the info... a couple follow-up questions:

-if finasteride increases your T levels, then wouldn't your libido increase when on finasteride? most people have the opposite effect...unless there's not a direct correlation between T and libido like i'm thinking there is?

-what's the correlation between T and DHT then? i.e., is DHT formed as a counterpart to T? or is there no connection between the two and they're formed independent from one another?

After being off of finasteride for 6 weeks there should NOT have been any more finasteride left in your system. Even if there was, it still would not make sense since your DHT level also dropped.

I think the better question is what time of the day did you have each of your blood tests done? Your testosterone levels are highest between 7am and 9am. Did you get a good night's rest before each test? Did you fast properly?


DHT is a metabolite of T. It is converted through a reaction via the enzyme 5-alpha-reductase, which also controls a few other reactions in your body.

 

[Donny J]

After being off of finasteride for 6 weeks there should NOT have been any more finasteride left in your system. Even if there was, it still would not make sense since your DHT level also dropped.

I think the better question is what time of the day did you have each of your blood tests done? Your testosterone levels are highest between 7am and 9am. Did you get a good night's rest before each test? Did you fast properly?


DHT is a metabolite of T. It is converted through a reaction via the enzyme 5-alpha-reductase, which also controls a few other reactions in your body.

both times, they were taken in the afternoon. the first time @ 4:00pm, and the second time at 3:00pm. I did not fast either time, but I did get decent rest both nights, so I would assume the results to be fairly comparable (which, would be neglecting the other points that redstar made about hormones constantly fluctuating).


so, my understanding is that because propecia inhibits the 5-ar enzyme from converting T into DHT, T should be higher when on finasteride, and DHT should obviously be much lower.

do we know what typical DHT levels are (in pg/mL measurements) for people on propecia? I've tried searching the forums, but it seems that everyone else's results are in different measurements.

 

[californiaoceans911]

both times, they were taken in the afternoon. the first time @ 4:00pm, and the second time at 3:00pm. I did not fast either time, but I did get decent rest both nights, so I would assume the results to be fairly comparable (which, would be neglecting the other points that redstar made about hormones constantly fluctuating).


so, my understanding is that because propecia inhibits the 5-ar enzyme from converting T into DHT, T should be higher when on finasteride, and DHT should obviously be much lower.

do we know what typical DHT levels are (in pg/mL measurements) for people on propecia? I've tried searching the forums, but it seems that everyone else's results are in different measurements.

Because you weren't fasting I could imagine that the levels would be different each time. As for Testosterone being much higher than your DHT level on finasteride, yes it should...but neither time were you actually on finasteride.

Oh wait I just noticed your units *face palm* in both cases you have 10 times as much Testosterone as you do DHT

As I pull up one of the papers (Gormley et al. 1990 Merck) I see that for almost every patient in their trial the subjects had 10 times as much T as DHT prior to finasteride administration. After 1 dose of 1mg of finasteride the ratio of T to DHT jumps from 10 to 40. Furthermore, testosterone levels did not change much and DHT was suppressed by a factor of 4.

Your blood tests look spot on.

 

[xRedStaRx]

both times, they were taken in the afternoon. the first time @ 4:00pm, and the second time at 3:00pm. I did not fast either time, but I did get decent rest both nights, so I would assume the results to be fairly comparable (which, would be neglecting the other points that redstar made about hormones constantly fluctuating).


so, my understanding is that because propecia inhibits the 5-ar enzyme from converting T into DHT, T should be higher when on finasteride, and DHT should obviously be much lower.

do we know what typical DHT levels are (in pg/mL measurements) for people on propecia? I've tried searching the forums, but it seems that everyone else's results are in different measurements.

Because you weren't fasting I could imagine that the levels would be different each time. As for Testosterone being much higher than your DHT level on finasteride, yes it should...but neither time were you actually on finasteride.

Oh wait I just noticed your units *face palm* in both cases you have 10 times as much Testosterone as you do DHT

As I pull up one of the papers (Gormley et al. 1990 Merck) I see that for almost every patient in their trial the subjects had 10 times as much T as DHT prior to finasteride administration. After 1 dose of 1mg of finasteride the ratio of T to DHT jumps from 10 to 40. Furthermore, testosterone levels did not change much and DHT was suppressed by a factor of 4.

Your blood tests look spot on.

Approximately 10% of T is converted to DHT, and 2-3% to E2. Testosterone usually increases by the amount of DHT suppressed.

Average DHT levels in men are around 600-750 pg/ml from what I've seen.