I've a question about injections, specifically the after effects. After about six or seven injections, starting a month ago, I developed a weird redness/swelling/itchiness in exactly the places I had been injecting. This also included dark red pinpricks where I had actually been pricked. What exactly is this? A friend thinks the estrogen had fallen out of suspension, but I fear an allergic reaction from the sesame oil.
For reference, subq ev 0.2mL at 5mg/mL every 4 days. Vial has been kept in the freezer, and warmed to body temperature before injections. It's from a licensed compounding pharmacy so should be completely fine. I've gone back to pills for now. ;-;
just to level set, this is getting beyond just HRT and into "I have to tell you I'm not a doctor" medicine. take everything I say with a large grain of salt.
redness/swelling/itchiness is a histamine (allergic) reaction. allergies are something that can come and go with time, repeated exposure/response can sensitize you to the allergen.
there are a few factors that go into this:
medication composition matters. HRT is a hormone dissolved into a carrier oil + (optionally) a preservative. allergic reactions to estradiol itself are vanishingly rare, the other two components are the usual suspects.
composition changes over time. you were storing your vial in the freezer, I have no idea if that matters but it is absolutely unnecessary. your friend suggested recrystallization because she also thought "this might matter but I'm not sure why", that's definitely not why but it's definitely an unnecessary complication.
for comparison I have three vials. two are in my freezer because I will not need a new one until late 2026, the one I'm using is a foot to the right of my keyboard. when it's done it will have been in use for two years. don't overthink storage.
injection technique also matters. if you are injecting at too shallow of an angle, the medication is deposited closer to the skin. it doesn't quite work like this, but it's useful to think of your skin as being the most sensitive to allergens because it's your first line of defense.
I overthought the hell out of injection angles + I was very skinny when I started, so I ended up accidentally injecting into the lower layers of my skin. investigating why I had itchy red lumps led to a lot of people saying "you're allergic", but I fixed it by adjusting my technique
just as a total shot in the dark, repeated freeze/thaw cycles might have degraded the stopper. over a period of months, the degraded stopper allowing enough oxygen exchange to degrade the solution in some way (my bet being carrier oil). it might be that you sensitized yourself with technique that was tolerable in the beginning and added up to an issue over time. it might be that your body doesn't like the carrier oil that supplier uses, but not enough to raise a stink immediately.
happily, you have so many options. you seem like you think along a scientific bent, I'm sure you can identify a lot of variables to tinker with here. at worst, transdermal RoAs are roughly identical in profile, the major difference being that dosing is a little more tricky. you can figure it out :)
p.s. it sounds like you're being prescribed this medication, this is where a doctor can come in handy. doctors often aren't very helpful until motivated, but they're easy to bait into discussing medicine. if you have to talk to one to renew your subscription to girl, take that as an opportunity to pick their brain. think of them as a contractor, if you had someone in to fix your sink it's normal to be curious about the process. they work for you :)
