Injecting Hormones
A lot of people on hormones inject them. Most people on testosterone do, at least to start with, and in parts of the US and elsewhere a growing number of people on feminizing HRT inject estradiol too. For most of them the medicine is the easy part. The needle is the bit they lie awake about.
This page is the practical picture: the two ways of injecting, where on the body, how people fit it into a week, what to do with the sharps, and which reactions are normal and which need a call. It isn't a substitute for being shown. Almost every prescriber or clinic will have a nurse walk you through your first injection, or will teach you over video, and that's the right way to learn the steps for your product. What follows is what helps to know before and after that lesson.
On this page
Under the skin or into muscle
There are two ways hormones are injected.
Intramuscular (IM) injections go into a muscle, usually the outer thigh, the side of the hip or the upper arm. This is the traditional route for testosterone and for injectable estradiol, and it's how the long-acting testosterone undecanoate is always given, by a nurse, every few months.
Subcutaneous (subq) injections go into the fat layer just under the skin, usually the belly or the front of the thigh, with a much shorter and finer needle. Many prescribers now offer subq for weekly testosterone and for estradiol, because it's less painful, easier to do on yourself, and for many people gives levels similar to IM at the same dose. Not every product is licensed for it and not every prescriber uses it, so it isn't your choice alone, but it's a fair thing to ask about if the IM needle is putting you off.
The medicine itself is usually an oil, which is why it's thicker than people expect and takes longer to push in than a vaccine. That's normal, and it's also why the needle used to draw it up is often wider than the one used to inject.
Where on the body
Your nurse or prescriber will show you the sites that suit your product and route. The common ones are:
- Subq: the belly, a couple of finger-widths away from the navel, or the front and outer thigh.
- IM: the outer middle third of the thigh, which is the easiest to reach yourself; the side of the hip (ventrogluteal), which many nurses prefer; and the upper arm for smaller volumes.
Rotate between sites, left and right, and don't inject the same spot week after week. Repeated injections in one place can leave hard lumps under the skin, and the medicine absorbs less predictably from scarred tissue. A simple pattern, alternating sides each week and moving a little each time, is enough.
Avoid anywhere that's bruised, broken, tattooed very recently or already sore. If you can feel a lump from a previous injection, go somewhere else.
At your first injection lesson
Ask the nurse to mark the safe area on your thigh or belly with a pen and take a photo of it. The first few times on your own, the hardest part is trusting that you're in the right place, and a photo settles that.
Doing it
The steps for your product are the ones you're taught. Across products the same habits keep coming up:
- Wash your hands and lay everything out on a clean surface before you start: the vial, the needles, the syringe, an alcohol swab, a plaster and the sharps bin.
- Check the vial: the right medicine, in date, clear and free of bits. Oils can go cloudy in the cold and clear again at room temperature.
- Use a fresh needle and syringe every time. Never share them and never reuse them. Blunt needles hurt more, and reused ones are an infection risk.
- Go slowly. Thick oil pushed in quickly is more painful and more likely to leave a sore lump. Ten seconds or so is not too long.
- Write it down: the date, the dose and the site. It's the record your prescriber will ask for when your levels look odd.
Warming a vial briefly in your hand thins the oil and makes the injection easier. Numbing cream, ice beforehand, and injecting at the same time each week all help people who find the needle hard.
Picking a day and an interval
Most short-acting testosterone is injected weekly or every two weeks; injectable estradiol ranges from every few days to every week or two, depending on the type. Your prescriber sets the interval, but it's a choice that can change, and it's worth understanding why.
After each injection your level rises to a peak over a day or two, then falls until the next dose. The longer the gap, the higher the peak and the lower the trough. On testosterone, big peaks push hematocrit up and can bring acne and irritability; deep troughs can bring tiredness and low mood in the last day or two before the shot. On estradiol, low troughs can let testosterone creep back up.
That's why many people end up splitting the same total dose into smaller, more frequent injections, weekly instead of fortnightly, or twice weekly instead of weekly. The average stays the same and the swings shrink. If you notice a pattern that lines up with your injection day, tell your prescriber: it's one of the easier things to fix.
Pick a day that's usually quiet, with time to do it calmly. Many people choose an evening before a day off, so any soreness has a night and a morning to settle.
When your blood test is booked
Check whether your prescriber wants it at the trough, just before your next injection, or at another point, and time the shot around it. A level taken at the wrong point in the cycle can send a dose change in the wrong direction.
What's normal afterwards, and what isn't
Normal: a little soreness for a day or two, especially after IM injections; a small bruise; a pea-sized lump under the skin after subq that fades over days. A drop of blood or oil at the site is nothing.
Worth mentioning at your next review: lumps that don't go away, the same spot always hurting, or bruising every time. Usually it's technique or site, and a nurse can watch you inject and suggest changes.
Needs a doctor the same day: a site that becomes hotter, redder, more swollen and more painful over a day or two, especially with a fever, which can mean infection; or any sign of an allergic reaction, such as a spreading rash, swelling of the face or lips, or difficulty breathing, which needs emergency help.
With long-acting testosterone undecanoate, a rare reaction can cause a cough, breathlessness or chest tightness within minutes of the injection. It's one reason those injections are given in a clinic and you're asked to stay for a short while afterwards. Risks and side effects covers testosterone's other effects.
If needles really aren't for you
Plenty of people never get comfortable injecting, and that's fine. A partner, friend or practice nurse can do it for you; many UK surgeries give long-acting injections every few months, so there's no self-injecting at all. If needles are a hard no, gels and patches exist for both testosterone and estradiol, at a higher monthly cost and with their own trade-offs. Testosterone and estrogen go through the forms.
I wouldn't let fear of needles be the reason you stay on a form that doesn't suit you, or the reason you skip doses. Either is a conversation worth having with your prescriber.
General information, not medical advice. Learn the injection technique for your product from a nurse or prescriber, and follow their instructions over anything here.
Frequently asked questions
Does injecting hormones hurt?
A little, mostly as a sting and some soreness afterwards. Subq injections with a fine needle tend to hurt less than IM, and going slowly helps. See doing it.
Can I inject testosterone under the skin instead of into muscle?
Many prescribers now offer subq for weekly testosterone, and it often gives similar levels. It depends on your product and prescriber. See under the skin or into muscle.
Why do I feel tired the day before my injection?
Often because your level is at its lowest just before the next dose. Smaller, more frequent injections can smooth that out. See picking a day and an interval.
What do I do with used needles?
Put them straight into a sharps bin and return it the way your area allows. Never put needles in household rubbish. See sharps and supplies.
I missed an injection. What now?
Don't double up. Check the instructions that came with your prescription or ask your prescriber or pharmacist how to get back on schedule; the answer depends on the product and how late you are.