Undecanoate (mis)information
(Image 1 from lowtadviser.com)
(Image 2 from apumn.com)
Testosterone undecanoate (I will be referring to it mostly as TU or test u) is a long-acting ester of testosterone than can be injected much less frequently than other known esters. It can be expensive but it’s a very promising option for those that struggle with injections. Recently I noticed what seems to be some misinformation about TU from Diyhrt.info. Don’t get me wrong, that website is mostly great, but it has some misleading text about the test u ester that’s kind of frustrating and could lead to trans men doing their injections in very ineffective ways. Its claim that it should be injected monthly does not seem to be backed up by any science and I cannot find any pharmaceutical companies recommending to use their product this way. It’s half life is much too long for it to make sense to use it like this. It should be injected every 10-14 weeks in doses of 750-1000mg. Here’s my evidence to back this up.
From drugs.com:
“Testosterone Undecanoate: 750 mg (3 mL) IM injection followed by 750 mg (3 mL) injected after 4 weeks, then 750 mg (3 mL) every 10 weeks thereafter”
From a pubmed study on the efficacy of testosterone undecanoate:
“750 mg testosterone undecanoate depot injection administered intramuscularly at 0, 4 and 14 weeks achieves serum testosterone levels in the normal range during a 10-week dosing interval”
From medicinenet.com:
“The recommended dose of testosterone undecanoate is 750 mg (3 ml) intramuscularly; followed by 750 mg (3 ml) intramuscularly after 4 weeks, then 750 mg (3 ml) intramuscularly every 10 weeks thereafter.”
From an information packet about Nebido (brand of injectable testosterone undecanoate):
“Nebido (1 ampoule / vial corresponding to 1000 mg testosterone undecanoate) is injected every
10 to 14 weeks.”
But for some reason, citing no evidence, diyhrt.info claims:
“These typically contain 1000 mg, which is usually too high, leading to excessive levels and large fluctuations … Because testosterone undecanoate builds up slowly, an initial loading dose of up to 2.5× your regular dose can be used to reach stable levels faster. For example, if your intended dose is 300 mg every three weeks, your initial loading dose may be 600 mg (300 × 2.5).”
They only recommend 150-400mg every 21-31 days, and I think their justification for this is that it leads to less severe fluctuations. Which does not seem to be true.
I cannot find any reliable source stating that more frequent injections of test u results in more stable levels, which is what diyhrt.info claims. In fact, the data seems to show that less frequent injects of long-acting esters (like test u) result in more stable hormone levels over long periods of time because they don’t peak weekly. It takes several weeks for your levels to fully peak on undecanoate. You can inject so much of it at once s because it releases extremely slowly over time.
Also. That’s not how loading doses work on TU. Like. At all. How “loading doses” work with test u is that you take 750-1000mg as your initial dose, and then inject the same amount again 4 weeks later. Then every 10 weeks you inject the same dose. It helps make your levels initially stabilize much more quickly. The only time I’ve ever heard of someone on TU change their dose (for loading dose) was making the loading dose 1000mg and injecting 750mg 4 weeks later, then 750mg at intervals of every 10 weeks like normal. The loading dose for TU should not be 2.5x the regular 750mg dose I think it’s crazy to recommend that. I can find no medical literature recommending what diyhrt.info recommends here.
And. 300 x 2.5 ≠ 600. I don’t want to make any accusations but I’m starting to wonder if this section was written by an LLM or something. This is just so easy to fact check. I have never seen this website and information source distribute so much misinformation. I want to stress that this is very unusual for them and they should remain a trusted site in the community. But this ain’t it, chief.
I don’t know how to get in contact with whoever is running diyhrt.info, but if you are reading this, I have a lot of respect for what you do and I apologize for any rudeness in what I’ve said. I just want people to be safe and receive accurate information about the things they’re putting in their bodies. Thank you for everything you do. I really hope you change this because this misinformation may be causing trans men to incorrectly dose themselves. It would also be nice if in the future the website could add studies that they got their information from so that we know what is written has some empirical evidence.
Thank you for your time.