T Nation

RLH and rFSH vs. hCG


I'm wondering why no one has used recombinant LH and/or rFSH for TRT. From what I understand, both are used in fertility medicine. I understand that hCG is cheaply made from pregnant women's urine, but there have been concerns about hCG. The common concern is some sort of prion disease from urine, even though the urine is sterile.

I think the advantages of using a combination of rLH and rFSH would be precise control of hormone levels, no issues of activating unintended receptors (what's actually in hCG?), and no antibody formation. You could take a blood test for LH and FSH levels, then alter your dose until your LH and FSH levels exactly match those of a healthy young male.

I guess hCG would be fine if FSH is unnecessary to maintain fertility or testicular hormone production, and if a proper hCG dose is known.

Does anyone have information or comments about rLH or rFSH? Specifically, does hCG actually address a lack of FSH in patients, if there's a need for FSH? Also, does hCG activate receptors such as those for prolactin?


I forgot to mention, I realize there's a halflife issue with regular LH, but that wouldn't be an issue with PEGylated LH. There could even be an undiscovered version of LH that's one amino acid different from human LH, which has a much longer halflife.

In addition to that, hCG only has a half life of ~12 hours, it's its effects which last several days.


I read about this a couple months ago, and from what I understand it is still prohibitively expensive right now to use on a regular basis...it is also not very well understood yet in the medical community due to its novelty.

Though I think this will be the HRT ancillary of the future once it gains more widespread acceptance...agree that exactly replacing the hormones mimicked by HCG is superior to current options...


Thanks for your input. Maybe I should put this in a different thread. But, if healthy testicular function is maintained through hCG, why wouldn't someone be able to discontinue TRT and then return to pre-TRT testosterone, LH, and FSH levels? There was a male birth control study that showed, after 3-6 months off, a few hundred Chinese men were able to return to normal sperm counts after 2.5 years of TRT which consisted of only 200mg of testosterone per week (no hcg, AI, or even PTC).

I've read that FSH is unnecessary for maintaining fertility because hCG can act like FSH to a small degree. Also, FSH is unnecessary to maintain healthy testicular function. Is this true? Is there science to support this idea, or have there been no studies on it yet?

I've read KSman say that hCG can raise intertestictular estrogen levels through intertestictular aromatization. I'm not expert in this field, like he is. But, my theory is that hCG contains prolactin, or fragments of other, similar, estrogen related peptides. hCG is just twice distilled urine after all... Do you think hCG itself could cause estrogen problems?

I'm not considering starting TRT until I'm at least 30. But, I'm interested in the topic, and maybe these question will be helpful to someone else.


I think you have some misconceptions regarding the extraction process of hCG; it is not distilled urine, it is extracted using ion-exchange chromatography and yields recovery rates of ~90% hCG. Steroid hormones such as estrogens do not elute with hCG. In addition, only small prion sequences (8-10 amino acid length) were found in hCG extracted from urine; further work would need to be conducted before we can conclude that prions are actually present in urine-extracted hCG. Also, the elimination half-life of hCG is 33 hours, which is significantly longer than LH (20 minutes).

In terms of adding polyethlyeneglycol to LH, hCG consists of two subunits, an alpha and a beta. The alpha subunit is identical to LH (and FSH, TSH), and the beta subunit is very similar to LH, with hCG having an additional 24 amino acids (you can think of this as nature's way of PEGylating LH).

In terms of FSH-activity; hCG does not have demonstrated direct FSH-activity. It exhibits indirect FSH-activity by raising intratesticular testosterone levels, which stimulates the Sertoli cells.


Ah, that clears things up. I had thought it was purified by weight. I imagined a giant vat of human urine being put into a centrifuge or something. I though hCG was just the name for the random collection of peptides in urine with a weight of, for example, 10-15 kDA. I don't understand how they can extract one peptide from urine in any sort of cost effective manne, it's pretty amazing.

So, the hCG on the market is typically 90% pure? Does the purity vary from manufacturer to manufacturer? What I meant by estrogen related peptides, is peptides which have an effect similar to the effect of estrogen. For example, I would consider prolactin similar to estrogen in some ways. There are so many peptides and peptide fragments in urine, I still think that "hCG" could have direct agonism for many receptors, not just the LH receptor. What I mean by "hCG" is whatever is sold under the name "hCG." Do you think that could be true?