T Nation

Potential Infection

I’m relatively new to TRT. As is commonly suggested on this site, I’ve been using 1/2” 28g insulin needles to inject my delts (alternating days).

All injections have been fine until now. I always swab the injection site, the rubber seal on the ampule, and ensure the needle doesn’t come into contact with any surfaces (any obviously don’t reuse needles).

Anyway, I injected roughly 12 hours ago as usual, and this time, I am now able to feel pain in my deltoid when I move or flex my arm (though not when stationary - at least yet). Additionally, it the skin appears to be slightly raised and hard beneath the injection site. It is definitely a bit warm to the touch. There isn’t any apparent redness (yet), however.

I worked out this morning after injecting, if that could have any impact.

From what I’ve read on here, it sounds potentially like a mild infection. Are there any steps I can take to prevent it from getting worse if it is? How long should I wait before seeking medical care?

I know antibiotics would probably be routine for something like this, but I’d like to avoid them at all costs as necessary, as I’ve been working quite diligently to repair my gut that was previously really fucked by antibiotics.

Any help would be appreciated. I know you are not doctors, but hopefully you are able to tell me whether this sounds fairly common and most likely innocuous or whether it requires urgent medical attention.


Edit: I should have thought of this sooner. Since starting TRT, when I get at all hot (brisk walking, working out, etc.), I become extremely itchy. I’m not sure if I’m allergic to the carrier oil (probably cottonseed since it’s test cyp) or some preservative. I’ve heard of exercise-induced histamine reactions/allergies. I never had this issue before starting T. Perhaps I’m allergic to the preparation and the manifestation becomes worse upon working out?

Initially, I just assumed T was increasing nitric oxide and thus blow flow to tissue, hence the itchiness.

Just a thought. Thanks for reading.

Time between injection and pain is 12 hours? Probably not an infection. Infections take time to build up and they take even longer to start causing pain. 12 hours seems pretty quick for that progression. People get infections from surgery that take days to manifest as pain. It’s still possible, but it’s less probable. Your most likely culprit is a subq leak. The oil leaked from the muscle into the subcutaneous area post injection. It happens sometimes and it can be painful. It also oftentimes presents as a lump. It’s nothing to worry about. Monitor the area for a few days and if it starts to get worse then yes, it’s an infection. But odds are it’s a leak and you can go about your daily life.

As far as an allergy to CSO… I would be pretty surprised. It’s a very, very uncommon allergen, and pruritus isn’t the most common symptom. Usually CSO allergies are more severe and include trouble breathing. The more likely answer is that something else is going on downstream as a result of the trt. What that is remains a mystery to me.


I’ve experienced a similar ‘bolus’ lump when I did shallow IM infections into small sites (delts and calves a couple of times, and once in the pectoral). The fact there is a lump almost right away suggests the oil didn’t quite get deep into the muscle but instead is, as Iron said, sitting in the subcutaneous layer and that isn’t comfortable. In fact were I ever to do subQ injections instead of IM, I’d only use small amounts of oil (say, 0.1 or 0.2ml/cc) - as the idea of putting larger (0.5ml/cc +) amounts in that way seems like a recipe for lumps like you describe. They do recede but it takes a day or so.

Solution for me was to use different needles for different sites. I rotate between calves, delts, pecs, lats, ventrogluteal and quads. Only the latter two get true ‘deep IM’ injections using 1 inch needles while the rest get 29G 0.5 inch insulin pins. And funnily enough delts used to cope with 1 inch pins quite well too, with no lumps, so long story short, you’ll need to consider the site, volume of oil and of course whether that 0.5 inch needle is allowing for shallow IM (which is OK where oil volume is fairly low) instead of subcutaneous (much less forgiving as oil volume increases).

Hope that helps and Happy Christmas to you and yours.


Thanks for the info. Happy holidays!

Thanks for the info. Assuaged my concerns a bit. Happy holidays!

Outline the affected area with a Sharpie, then re-eval periodically for change in extent. If it spreads, get thee to an urgent care clinic.

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Your arm should be better or worse by today, how is it?

The pain has definitely gone down! I think you guys were right: The “IM” injection probably was right on the edge and most of it leaked into the subscutaneous tissue.

Definitely relieved.

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