Free Testosterone Declines with Propecia Use?
Dear Dr. Rassman,
I am a 31 year old male who has been on Propecia for 5 years. After getting bloodwork done, it was discovered that while my Total Testosterone was high, the percentage of Free Testosterone was proportionately low.
Then, I discovered an article from an Egyptian medical journal entitled “Effect of Oral Finasteride on Serum Androgen Levels and Androgenic Alopecia in Adult men”, which found that all men in the experimental group experienced a decline in free testosterone after taking Propecia relative to no change for those taking a placebo. Were you aware of this? Does this not add to the growing body of literature showing how dangerous Propecia really is?
The main point of why Propecia (finasteride 1mg) works is because it changes DHT hormone levels. DHT is the result of testosterone catabolism (it is a byproduct of testosterone metabolism). So to say Propecia affects testosterone in some way is valid, but I cannot say what this really means. The study you refer to included only 30 men and it does not go on to state what the implication is or what the significance is of the findings.
For those interested, the study can be found here (PDF file).
These are the type of articles that can cause confusion and add fuel to the never-ending debate on Propecia depending on how you parse the information presented. Anyone can quote articles and infer what they want, but the real meaning or significance is unclear. At least this is interesting reading. Let the debates begin… or rather, continue!
doctor…as an athlete, this is something about propecia which interests me greatly – but there just doesn’t seem to be enough information available about it.
Would there be anything to stop doctors like yourself taking bloodwork of patients before and during finasteride use so that you (as someone in a position who sees finasteride users daily) could report back to us – so we could make informed decisions taking into account not only our hair, but other matters also of interest to us like hormone levels?
Would really appreciate a response. Thanks.
but, having just scanned the study – this isn’t looking good for men who want to sustain athletic performance..and even libido while on finasteride :(
How are those PGD2 inhibitors getting on!!!!
Hi Mark some of us are athletes who’ve continued to operate at a very high level with years of finasteride use. Its always possible that propecia blunted our maximum potential in some way or delayed recovery by a percentage point or two – we’ll probably never know – but I’m
Not the only one who comments here who has had a higher level athletic career.
Propecia clearly affects androgens but if it destroyed athletes then I know quite a few record books that would need re-writing urgently!
The conclusion that this study states how dangerous Propecia really is, is quite a contradictory when you actually read it.
Most men in the medicated group experienced a 25% drop in free Testosterone levels, yet only one experienced any side effect as a result (decrease in libido) which went away after discontinuing treatment. This is yet another testament to how safe this drug is.
As Dr. Rassman astutely pointed out, the researchers did not feel it was even noteworthy enough expand on the implications of this. Rather, I suspect the anti-Propecia fanatics are having a heyday with this one and drawing their own conclusions.
From this, any objective individual would conclude either:
a) The study contained a bias or flaw in measurement that skewed the data that was obtained
b) A 25% decrease in free testosterone levels has no tangible side effects or repercussions in the general population
I am leaning more towards a. I have been taking finasteride for 4 years, and even getting up in my 30’s am in the best physical shape of my life. Finasteride has never been shown to stunt muscle development or growth in any study I’ve seen. If finasteride lowered FT levels by 25% across the board, you would expect someone might have noticed the obvious implications.
The fact of the matter is, you can delve in to as many studies as you want and find correlations that look scary as hell. I see this constantly, but it doesn’t change the fact that Propecia has a ridiculously rate of side effects and has not once been found to cause side effects that didn’t resolve shortly after discontinuation of treatment.
The study itself concludes that “Oral finasteride was effective and safe treatment of mild to moderate AGA”. I suspect many people will still read this study and conclude it is dangerous.
I’m not calling the drug dangerous but any athlete will know that a reduction in free testosterone levels is a real negative effect…some of those studied had these levels decrease by as much as 40% which to me as someone who considers taking fin is a major turn off. That is a very large drop by any standards. The opposite effect of performance enhancing steroids.
I have no anti propecia agenda because i would love for it to be right for me – but i wish it would work for hair without any other emasculing effects. Thats why it would be good to see a larger scale study on this.
I’m not a doctor, but as far as I understand it, Free Testosterone is only decreased when your body releases Sex hormone-binding globulin (SHBG). At least, that’s the only thing a Free-T blood test exists to measure: how much of your testosterone is unbound by SHBG. So, the real question becomes: why would finasteride cause your body to release SHBG?
It’s possible that your body increases its sensitivity to testosterone (by, eg, increasing available testosterone receptors) as a result of losing so much DHT (which has a much greater affinity for the testosterone receptor). As such, you may actually be getting more out of the testosterone you have, and thus need less hormones for the same bodily effects.
To put it another I’m suggesting that the presence of super-potent DHT results in a blunted response to regular testosterone. With less DHT around to compete with, cells might increase their ability to grab up regular testosterone. In a high total-T environment, this would lead to your body releasing SHBG, as a response to *excessive* androgen activity. The results of this study suggest that your body actually has too much testosterone on finasteride (or at least is acting as such).
There was recently an article linked on this site showing that finasteride increased androgen receptor counts in abnormal prostate cells, so it’s not entirely unfounded to suggest it may be happening in normal cells as well.
Don’t people realise how serious this is? No man should want to decrease their free testosterone! This is why an alternative MUST be found for hair loss. As safe as you want to pretend fin is – in the long run you are doing damage to your body by lowering your male hormones.
Did anyone notice the clear mistakes in the narrative portion of the study? If you look at the actual data tables, they are different than the narrative analysis. For example, if you read the section where it says:
“Statistical analysis of hormonal assay revealed
that, serum levels of (TT) were increased significantly
compared to baseline levels in treated group
when compared to placebo group from a median of
(427 ng/dl) at baseline (normal range 241-827
ng/dl) to (490 ng/dl) at month 9, whereas serum
levels of (FT) were decreased from baseline values
at the endpoint of treatment when compared to placebo
group, in which no changes were noted before
or after treatment from a median of (7.0 ng/dl) at
baseline normal range (8.7-54.7 ng/dl) to (4.0
ng/ml). Serum levels of DHT were reduced markedly
from median (44.6 ng/dl) at baseline (normal
range 30 – 85 ng/dl) to (14.0 ng/dl) at month 9 (Tables
3, 4 & 5).”
But looking at the actual tables that are referenced, you will find that the median level of free testosterone (FT) in the treated group at the start of the study was actually 25.33 ng/dl. At the end of the study the median was 18.40 ng/dl, which would still be within the normal range of (8.7-54.7 ng/dl)for free testosterone levels. But the narrative part of the study says that the median FT level at the start of the study was 7.0 ng/dl (out of range already before treatment), which dropped to 4.0 ng/dl after treatment with finasteride. How can that be right? The tables referenced after that section do not support that.
I caught other mistakes as well when I began adding up the numbers in the tables. The calculation of the median average for TT and DHT appears to be off as well.
I am a lay person and because of the errors that appear to be blatant when I casually read this study, I don’t think it can really be trusted with regards to the data compilation. How does stuff like this get published when there are mistakes that are so easy to locate? I would like to speak with the authors of the study to see if they recognize where it doesn’t add up.
Did anyone also notice all of the grammatical mistakes and sentences that do not sound right?
“No any significant changes in serum LH, FSH
and PRL form baseline levels and this indicate that
finasteride has no significant effects on the hypothalamic-
pituitary gonadal axis.”
and “there were no any hormonal or clinical changes from baseline.”
It just doesn’t appear to be a good study, and the credibility of the authors seems to be in question as they couldn’t even calculate the averages right.
You make some very good points there TH, I am taking a look at this and seeing the same errors. I also spent a while searching, but couldn’t find a single other study that finds anything similar to these results. I’m questioning the validity of this study. If the interpretation of the data is incorrect, I am wondering how accurate the data was in the first place.