Aug 302014
Image of needle and syringe - click through to see source

Needles and syringes no longer look like this. Isn’t that wonderful?

Testosterone therapy for transgender men, and others who desire testosterone supplementation, typically involves intramuscular injections of testosterone. Intramuscular injections deliver the medication deep within a large muscle — typically a thigh muscle. From there the hormone can slowly work its way into the bloodstream to do its magic. Few other options exist, and those that do are either expensive or less effective (e.g., creams). Testosterone should not be taken as a pill because it’s very bad for the liver in that form. One possible alternative that has been discussed recently is subcutaneous testosterone injections.

Subcutaneous injections go just under the skin. Most people don’t get subcutaenous injections. The most common subcutaneous injection may be insulin injections for people with diabetes. Subcutaneous injections are also how fluids are given to cats in veterinary care.

Subcutaneous testosterone has been in sporadic recent use for trans men without any research showing how well it works. But that’s changed now with the publication of the article I’m going to summarize. 🙂 So let’s hop into it!

This was a study involving 36 male-identified trans youth from ages 13-24 (minors had parental consent). None had been exposed to hormones before. Hormone levels and other lab values were measured at the beginning and after six months.

For those interested in the specific technicalities of how the hormone was given, keep reading this paragraph. For those not, skip down to the next one! They were given testosterone cypionate suspended in sesame oil that was made at a local compounding pharmacy. The young men were given the injections by the clinical staff at first, but slowly taught to self-inject. Dosing was biweekly and started at 25mg per week, slowly increasing after that for some with a final dose ranging from 25-75mg.

So what did they find? How did it go? Positively!

About 92% of the young men in this study had testosterone levels in the “male” range at the 6 month check up. Similar goes for estrogen levels — by that 6 month check up their estradiol levels were down in the “male” range too. 85% of the young men who had been menstruating had stopped by that 6 month check up. Most periods stopped roughly around the 3 month mark. Other factors, like hemoglobin (red blood cell concentration) and cholesterol shifted but were not of clinical significance.

Two of the young men had allergic reactions to the sesame oil and were switched to cottonseed oil. This is a pretty well known reaction that happens in intramuscular injections too. Some also noticed small bumps around where they injected for a few days after injection. Those were the only reported side effects. Nobody reported unhappiness with their testosterone treatment method or asked to be switched to a different method.

All in all, a well put together study. Subcutaneous injection of testosterone so far appears to be a possible alternative to intramuscular injection. But it’s worth noting that commercial testosterone is intended for intramuscular injection and that type is not what was tested here. It may not be safe or effective to inject an intramuscular formulation as a subcutaneous one — ask your physician before changing how you use your medications!

As always: this is just one study. More need to be done to confirm these results. Regardless, I think these are good first results and look forward to seeing more.

Study was published in LGBT Health. Abstract is publicly available.

Disclaimer: I have personally met Dr. Olson (lead author of this study), worked with her in a small capacity, and have attended her talks at conferences. My interactions and impressions of her may have biased my interpretation on this study. However, I do my best to keep those preconceptions from affecting my judgment.