Procedure guide
How to Inject Testosterone
The procedure, with the source of every step named — and the steps that have no source named too.
- Reviewed by
- Alpha Health Finder Editorial Team
- Last reviewed
This page is about the procedure, not the product. The compound page for testosterone cypionate already carries the seven-step vial checklist — confirm the diagnosis the label requires, inspect the oil, clean the stopper, draw, expel air, inject, log it — and its sixth step ends by handing the rest over: your prescriber will confirm site and technique. What follows is what sits behind that sentence.
Injection technique is mostly transmitted as folklore. Warm the vial, ice the site, always aspirate, never aspirate, Z-track everything: all of it circulates as instruction and very little of it arrives with a citation. So every step, site and troubleshooting entry below is tagged with where it came from — an FDA label, a public-health body, a published trial, or nobody. Where the honest answer is nobody, the page says that instead of picking a side.
One caveat runs through the whole page. The most detailed public guidance on intramuscular injection in the United States is CDC’s, and it is written for vaccines: small aqueous volumes into the deltoid or the thigh. Testosterone cypionate is a viscous oil that its label sends deep into the gluteal muscle. Much of the technique transfers and some of it does not, and every CDC quote here is labelled as vaccine guidance rather than quietly repurposed.
What this page does not cover
These live elsewhere on the site and are not restated here.
- Testosterone cypionate — compound page
The vial-side checklist: the two morning testosterone measurements the label requires before therapy, inspecting the oil, swabbing the stopper, expelling air, storage. Product-specific, and not repeated here.
- Testosterone cypionate 200 mg/mL protocol
The arithmetic: a prescribed dose in milligrams converted to a volume and to marks on a barrel, for that vial strength. This page never tells you how much to draw.
- Testosterone dose calculator
The same conversion for any strength and any injection interval, including splitting a weekly dose.
- Insulin syringe conversion chart
Units-versus-millilitres on every barrel, and the reason no page here prints a graduation interval as a fact.
The procedure
- 1
Find the landmarks before you open anything
Locate the site while both hands are still clean and there is no needle in either of them. CDC describes two ways to define a gluteal injection by bone you can feel through skin: laterally and superior to a line between the posterior superior iliac spine and the greater trochanter, or the ventrogluteal site, which is the centre of a triangle bound by the anterior superior iliac spine, the tubercle of the iliac crest and the upper border of the greater trochanter. The difference between a palpated landmark and “the upper outer quarter” is the difference between a location and a guess.
Public-health guidance“If the gluteal muscle must be used (e.g., because of reduced anatomic site availability), care should be taken to define the anatomic landmarks.”
CDC, Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book), Chapter 6: Vaccine Administration - 2
Draw through one needle and inject through a different one
A luer-lock barrel takes a detachable needle, which is the reason it is the barrel for an oil rather than an insulin syringe with its needle moulded on. Draw through a wide gauge, because cold cottonseed oil moves slowly through a fine one, then change to a finer needle to inject. CDC’s adult intramuscular table gives 22- to 25-gauge at 1 to 1.5 inches. The wider drawing gauge is a supply convention with no published specification behind it and is listed as such in the ledger below, and the pain benefit often claimed for the swap is not established — the 2021 systematic review found the evidence on changing the needle conflicting.
Public-health guidance“Most adolescents and adults will require a 1- to 1.5-inch (25–38 mm) needle to ensure intramuscular administration.”
CDC, Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book), Chapter 6: Vaccine Administration - 3
Hands first, then the skin, then wait for it to dry
Hand hygiene comes before anything is unwrapped. Swab the skin over the site you located with a sterile alcohol swab and let it air dry rather than wiping or fanning it — the drying is the disinfection, and alcohol still wet on the skin is also what stings on insertion. The vial-side aseptic steps, swabbing the stopper included, live on the compound page and are not repeated here.
Public-health guidance“Cleanse the skin with a sterile alcohol swab and allow it to dry.”
CDC, Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book), Chapter 6: Vaccine Administration - 4
Insert at ninety degrees, into the thickest part of the muscle
CDC’s adult intramuscular technique is a right angle to the skin with the skin spread tight rather than the tissue bunched, and the target is the middle of the muscle where it is thickest, not its edge. The Depo-Testosterone label is explicit that this is a deep injection into the gluteal muscle, which is a deeper site than CDC’s needle table was drawn for.
Public-health guidance“IM injections are administered at a 90-degree angle to the skin and, for most adult patients, the skin is spread and the tissues are not bunched.”
CDC, Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book), Chapter 6: Vaccine Administration - 5
Aspiration: understand the gap before you decide
This is the most argued step in the subject and the least resolved. CDC’s position is unambiguous and is about vaccines: aspiration is not recommended, it was adopted for theoretical reasons and never evaluated, it can increase pain through longer needle-dwelling time and wiggling of the needle, and there are no reports of anyone being injured by failing to do it. No FDA label and no US public-health body has published a position on aspirating before an oil-based intramuscular testosterone injection, which is a larger, slower, deeper depot injection than anything CDC’s statement covers. The Depo-Testosterone label says only that the product must not be given intravenously. This page therefore does not tell you to aspirate and does not tell you not to; the instruction that has standing is the one from the prescriber who taught you.
Public-health guidance“Aspiration is not recommended before administering a vaccine.”
CDC, Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book), Chapter 6: Vaccine Administration - 6
Withdraw, and cover the site only if it bleeds
Withdraw along the line the needle went in. A bead of blood at the puncture is common enough that CDC’s own sequence treats covering the site as conditional rather than routine. If the problem is pain rather than bleeding, the 2021 systematic review found manual pressure over the site reduced injection pain across four studies (standardised mean difference −0.85, 95% CI −1.36 to −0.33), while noting very high unexplained heterogeneity between the studies it pooled.
Public-health guidance“Apply an adhesive bandage to the injection site if there is any bleeding.”
CDC, Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book), Chapter 6: Vaccine Administration - 7
Do not recap, cut, or pull the needle off
Recapping is where most needlestick injuries happen, and CDC’s instruction is that the used needle is not recapped, not cut and not detached before disposal. The syringe goes into the container as one assembled unit, immediately, and CDC specifies what the container has to be: closable, puncture-resistant, leakproof on sides and bottom, and labelled or colour-coded.
Public-health guidance“Used needles should not be recapped or cut or detached from the syringes before disposal.”
CDC, Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book), Chapter 6: Vaccine Administration - 8
Put it in a sharps container, and act on it at three-quarters full
FDA asks for an FDA-cleared sharps container, which is rigid plastic and carries a printed line marking the point at which it should be considered full. Deal with it at about three-quarters full and follow your community’s disposal route from there — the route differs by state, so the container is the national part of the answer and the disposal is not. Where no cleared container is available, FDA describes a heavy-duty plastic household container with a tight-fitting, puncture-resistant lid as the fallback, which is a fallback and not an equivalent.
Public-health guidance“The FDA recommends that used needles and other sharps be immediately placed in FDA-cleared sharps disposal containers.”
FDA, Sharps Disposal Containers — Safely Using Sharps at Home, at Work and on Travel
Where to inject, and how to find it
Ventrogluteal
- Landmarks:
- The centre of a triangle bound by the anterior superior iliac spine, the tubercle of the iliac crest, and the upper border of the greater trochanter — all three bony and findable through skin.
- Trade-off:
- The only site here with a head-to-head pain finding behind it: the 2021 systematic review found injections at the ventrogluteal site hurt less than at the dorsogluteal site across two studies (standardised mean difference −0.43, 95% CI −0.81 to −0.06). It is also the hardest of the four to reach on yourself.
“A gluteal muscle injection should be administered laterally and superior to a line between the posterior superior iliac spine and the greater trochanter or in the ventrogluteal site, the center of a triangle bound by the anterior superior iliac spine, the tubercle of the iliac crest, and the upper border of the greater trochanter.”CDC, Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book), Chapter 6: Vaccine Administration
Dorsogluteal (upper outer buttock)
- Landmarks:
- Laterally and superior to a line between the posterior superior iliac spine and the greater trochanter.
- Trade-off:
- This is the site the Depo-Testosterone label actually names, and the only site any testosterone label names. It is also the region CDC avoids in infants and children over sciatic nerve injury documented after antimicrobial injections into the buttock — a caution about the anatomy, not a finding about testosterone.
“Intramuscular injections should be given deep in the gluteal muscle.”Depo-Testosterone (testosterone cypionate injection, USP) — FDA label, Pharmacia & Upjohn, ANDA085635, via DailyMed
Vastus lateralis (anterolateral thigh)
- Landmarks:
- The outer front of the thigh, injected into the thickest part of the muscle belly between hip and knee.
- Trade-off:
- Easy to reach on yourself and one of the two sites CDC recommends for intramuscular vaccines in adults. The Depo-Testosterone label does not name it, so using it for testosterone is practice rather than labelling — a distinction this site makes explicit rather than blurring.
“As with children and adolescents, the vastus lateralis muscle in the anterolateral thigh is an alternative site if the deltoid sites cannot be used.”CDC, Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book), Chapter 6: Vaccine Administration
Deltoid (upper arm)
- Landmarks:
- CDC names the muscle and illustrates the site rather than describing its boundaries in text, so there is no landmark sentence here to quote.
- Trade-off:
- CDC’s preferred site for adult intramuscular vaccines, which are small volumes. The Depo-Testosterone label does not name it. The millilitre ceiling people quote for a deltoid injection is convention — no label and no CDC table states one, so this page does not print a number.
“For adults, the deltoid muscle is recommended.”CDC, Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book), Chapter 6: Vaccine Administration
What “draw 0.5” means depends entirely on the barrel
A 1 mL luer-lock, drawn to 0.5 mL — half the barrel. The same instruction read off a 100-unit insulin barrel is 0.5 units, one two-hundredth of a millilitre, and a two-hundredth of the intended dose. The barrels are not interchangeable and neither are their numbers.
Which barrel, and what comes on the end of it
Read off src/lib/syringes.ts, the same record the dose calculator and the conversion chart use. The two luer-lock rows are the ones that matter for an oil; the insulin rows are here because reaching for one by mistake is the single most common error in this subject.
| Barrel | Numbered in | Holds | Needle suppliedgauge | Needle length | Needle detachable? |
|---|---|---|---|---|---|
| 30-unit insulin (0.3 mL) | units | 30 units0.3 mL | 29–31G | 5/16–1/2 in (8–13 mm) | No — fixed |
| 50-unit insulin (0.5 mL) | units | 50 units0.5 mL | 29–31G | 5/16–1/2 in (8–13 mm) | No — fixed |
| 100-unit insulin (1 mL) | units | 100 units1 mL | 29–31G | 5/16–1/2 in (8–13 mm) | No — fixed |
| 1 mL luer-lock | mL | 1 mL | 18–21G to draw, 22–25G to inject | 1–1.5 in (25–38 mm) for intramuscular | Yes |
| 3 mL luer-lock | mL | 3 mL | 18–21G to draw, 22–25G to inject | 1–1.5 in (25–38 mm) for intramuscular | Yes |
Gauges and lengths are the commonly supplied ranges, not a clinical instruction — needle selection belongs to the prescriber. The distance between the marks on your barrel is deliberately absent: no manufacturer documents it. See the insulin syringe conversion chart, which prints “Not documented” for the same reason.
Needle length and gauge for an intramuscular injection in an adult
Reproduced in full from CDC’s Pink Book, chapter 6, table “Needle Length and Gauge: Adults (age 19 years or older) for Intramuscular Injection”. This is vaccine guidance. There is no equivalent published table for oil-based intramuscular testosterone, and this one is here because it is the closest documented thing, not because it was written for this drug.
| Body weight | Needle length | Gauge |
|---|---|---|
| Less than 130 lbs (60 kg) | 1-inch (25 mm)* | 22- to 25-gauge |
| 130–152 lbs (60–70 kg) | 1-inch (25 mm) | 22- to 25-gauge |
| Men, 153–260 lbs (70–118 kg) | 1- to 1.5-inch (25–38 mm) | 22- to 25-gauge |
| Women, 153–200 lbs (70–90 kg) | 1- to 1.5-inch (25–38 mm) | 22- to 25-gauge |
| Men, greater than 260 lbs (118 kg) | 1.5-inch (38 mm) | 22- to 25-gauge |
| Women, greater than 200 lbs (90 kg) | 1.5-inch (38 mm) | 22- to 25-gauge |
*Some experts recommend a 5/8-inch needle for men and women weighing less than 60 kg; if used, skin must be stretched tightly and subcutaneous tissues must not be bunched. †The vastus lateralis muscle of the anterolateral thigh can also be used. CDC’s table names the deltoid as the preferred site for these lengths; the Depo-Testosterone label names the gluteal muscle, which is a deeper site than the table was drawn for.
When it does not go to plan
The oil will not draw, or the needle blocks part-way through
Cold testosterone cypionate is thick — the label’s own vehicle is cottonseed oil — and crystals form in it if the vial has been stored below the labelled 20–25 °C. The label’s fix is warming and shaking the vial, which is a solubility instruction and not a comfort one. The other half of the answer is the drawing needle: a wider gauge moves oil faster, though the 18–21G range commonly supplied for a luer-lock is a supply convention rather than a documented specification.
“Warming and shaking the vial should redissolve any crystals that may have formed during storage at temperatures lower than recommended.”Depo-Testosterone (testosterone cypionate injection, USP) — FDA label, Pharmacia & Upjohn, ANDA085635, via DailyMed
The site aches for a day or two afterwards
That is a listed adverse reaction on the label rather than a sign the technique went wrong. For pain during the injection itself the 2021 systematic review found manual pressure over the site (four studies, standardised mean difference −0.85) and rhythmic tapping over it (three studies, −2.95) both reduced pain, with the authors flagging very high unexplained heterogeneity. Pain that worsens over days, spreads, or arrives with fever or swelling is a different problem and belongs with a clinician the same day.
“Inflammation and pain at the site of intramuscular injection.”Depo-Testosterone (testosterone cypionate injection, USP) — FDA label, Pharmacia & Upjohn, ANDA085635, via DailyMed
It bleeds when the needle comes out
CDC treats this as conditional rather than as a complication: cover it if it happens. Pressure over the puncture for a few seconds is the ordinary response. Bleeding that does not stop, or a bruise that keeps spreading, is worth a call — particularly for anyone on an anticoagulant.
“Apply an adhesive bandage to the injection site if there is any bleeding.”CDC, Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book), Chapter 6: Vaccine Administration
Would warming the vial make it hurt less?
No published evidence says so. The 2021 systematic review looked at this directly across 29 studies of intramuscular injection technique and reported that warming the injectate did not reduce pain. The label’s warming instruction exists for an entirely different reason — redissolving crystals — and the two get conflated constantly. Warm the vial if crystals have formed; do not expect it to change how the injection feels.
“The effect of changing the needle after drawing up the injectate on injection pain was conflicting and warming the injectate did not reduce pain.”Ayinde O, Hayward RS, Ross JDC. The effect of intramuscular injection technique on injection associated pain; a systematic review and meta-analysis. PLoS One 2021;16(5):e0250883
Can I draw and inject with the same needle, or go back into the vial with a used one?
A 10 mL vial is a multidose vial, and CDC’s rule for one is that anything entering it is sterile — a needle that has already been through skin is not. Read the context honestly, though: CDC’s safe injection recommendations are written about transmission between patients in a clinic, not about one person and their own vial, and CDC has published nothing on the single-user case. The mechanical argument for changing the needle is separate and simpler — a point dulled by a rubber stopper goes in worse — and even that has no clean evidence behind it: the 2021 review found the effect of changing the needle after drawing up on injection pain conflicting.
“If multidose vials must be used, both the needle or cannula and syringe used to access the multidose vial must be sterile”CDC, Safe Injection Practices to Prevent Transmission of Infections to Patients (Standard Precautions III.A.1.b and recommendations IV.H)
Blood appears in the syringe when I pull back on the plunger
There is no sourceable answer to give here and this page will not invent one. The only relevant statement on the Depo-Testosterone label is that the product must not be given intravenously. The only US guidance on aspiration itself is CDC’s, and it is written about vaccines at sites where, in CDC’s words, the vessels are too small for an intravenous push. What to do at this exact moment is a question to settle with the prescriber who taught you the technique, before it happens rather than during it.
“DEPO-Testosterone Injection is for intramuscular use only. It should not be given intravenously.”Depo-Testosterone (testosterone cypionate injection, USP) — FDA label, Pharmacia & Upjohn, ANDA085635, via DailyMed
What we could not source
Widely taught techniques we went looking for and could not anchor to a label, a public-health body or a trial. Each entry names what was searched and what this page does instead.
Aspirating before an oil-based intramuscular testosterone injection
Searched: The Depo-Testosterone SPL (DailyMed setid cfbb53d4-b868-4a28-8436-f9112eb01c39) in full; CDC’s Pink Book chapter 6; CDC’s safe injection practice recommendations III.A.1.b and IV.H.1–IV.H.8; PubMed for aspiration in intramuscular testosterone administration.
What this page says: CDC’s statement that aspiration is not recommended is explicitly about vaccines, at sites where it says the vessels within reach of a needle are too small to allow an intravenous push. Nothing addresses an oil depot in the gluteal muscle. Step 5 states the gap and gives no instruction in either direction.
The Z-track technique
Searched: PubMed. The pooled figure below comes from the 2021 systematic review and meta-analysis of intramuscular injection technique.
What this page says: Reported, not recommended. The review found insufficient evidence on the benefits of Z-track for injection pain across two studies (standardised mean difference −0.20, 95% CI −0.41 to 0.01). The page states the finding and does not turn it into a step.
Warming the vial so the injection hurts less
Searched: The Depo-Testosterone label and the 2021 systematic review.
What this page says: The label warms the vial to redissolve crystals; the review found warming the injectate did not reduce pain. The page keeps the two purposes apart rather than letting one borrow the other’s authority.
Icing the site before or after the injection
Searched: PubMed. The nearest published comparison is the review’s “cold needle technique”, which chills the needle rather than the skin.
What this page says: Insufficient evidence even for that nearest technique (two studies, standardised mean difference −0.73, 95% CI −1.83 to 0.37), and nothing at all on icing the skin for this drug. Icing is left out of the procedure rather than mentioned in passing.
A maximum volume per site — the “no more than 2 mL in a glute” rule
Searched: The Depo-Testosterone label, CDC’s Pink Book needle and site tables, and CDC’s safe injection practice recommendations.
What this page says: No millilitre ceiling appears in any of them. Where a reader would expect a number, this page prints: not documented.
18–21G to draw, 22–25G to inject
Searched: The injecting range is CDC’s adult intramuscular table and is quoted as such. For the drawing gauge, the manufacturer listings and FDA device records already worked through for the insulin syringe conversion chart.
What this page says: No manufacturer or agency states a drawing gauge. It is a supply convention recorded in syringes.ts, and it is labelled convention on this page rather than instruction.
How far apart the marks on your barrel are
Searched: Recorded in syringes.ts: embecta and BD product families, UltiMed/UltiCare, Nipro, Exelint, HTL-Strefa, B.Braun, Medline, Cardinal/Monoject, Terumo, four 510(k) summaries, and full-text GUDID searches.
What this page says: Not documented by any manufacturer. This page prints no graduation interval and defers to the insulin syringe conversion chart, which prints “Not documented” for the same reason. Count the lines on the barrel in your hand.
Frequently asked questions
- What size needle do you use for a testosterone injection?
- CDC’s adult intramuscular table gives 22- to 25-gauge at 1 to 1.5 inches (25–38 mm), rising to a flat 1.5 inches for men over 260 lbs (118 kg) and dropping to 1 inch for anyone under 130 lbs (60 kg). That table is vaccine guidance and the deltoid is the site it assumes, while the Depo-Testosterone label sends the injection deep into the gluteal muscle — a deeper target than the table was drawn for. Drawing is usually done through a wider 18–21G needle, which is a supply convention and not a documented specification.
- Do you aspirate before injecting testosterone?
- Nobody has published an answer for testosterone. CDC states that aspiration is not recommended before administering a vaccine, that it was adopted for theoretical reasons and never evaluated scientifically, and that there are no reports of any person being injured because of failure to aspirate — but that is about vaccines, at sites where CDC says the veins and arteries within reach of a needle are too small to allow an intravenous push without blowing out the vessel. The Depo-Testosterone label says only that the product must not be given intravenously. This page declines to instruct either way and points the question at your prescriber.
- Where do you inject testosterone cypionate?
- The label names one site: deep in the gluteal muscle. CDC gives the landmarks for locating a gluteal injection — laterally and superior to a line between the posterior superior iliac spine and the greater trochanter, or the ventrogluteal triangle. A 2021 systematic review of 29 studies found ventrogluteal injections hurt less than dorsogluteal ones across 2 studies (standardised mean difference −0.43, 95% CI −0.81 to −0.06). The thigh and the deltoid are used in practice but are not named on the testosterone label.
- Does warming the vial make a testosterone injection hurt less?
- The evidence says no. A 2021 systematic review and meta-analysis covering 29 studies of intramuscular injection technique reported that warming the injectate did not reduce pain. Warming does have a documented purpose on the Depo-Testosterone label, but a different one: warming and shaking the vial redissolves crystals that form if it has been stored below the labelled 20–25 °C. Warm the vial for the crystals, not for the comfort.
- Does the Z-track technique reduce injection pain?
- Not on the evidence available. The 2021 systematic review found insufficient evidence on the benefits of the Z-track technique on injection pain, pooling 2 studies to a standardised mean difference of −0.20 with a 95% confidence interval of −0.41 to 0.01 — an interval that crosses zero. A separate randomised study of 60 patients receiving intramuscular diclofenac found Z-track reduced drug leakage but not pain severity. Neither study used an oil-based testosterone ester.
- How full can a sharps container get before you get rid of it?
- FDA’s guidance is to act at about three-quarters (3/4) full and then follow your community’s disposal route, and FDA-cleared containers carry a printed line marking that point. Needles go in assembled: CDC is explicit that used needles should not be recapped or cut or detached from the syringes before disposal, because recapping is where most needlestick injuries happen. If no cleared container is available, FDA describes a heavy-duty plastic household container with a tight-fitting, puncture-resistant lid as the fallback.
Sources
- [1]Depo-Testosterone (testosterone cypionate injection, USP) — FDA label, Pharmacia & Upjohn, ANDA085635, via DailyMed
- [2]CDC, Epidemiology and Prevention of Vaccine-Preventable Diseases (Pink Book), Chapter 6: Vaccine Administration
- [3]CDC, Safe Injection Practices to Prevent Transmission of Infections to Patients (Standard Precautions III.A.1.b and recommendations IV.H)
- [4]FDA, Sharps Disposal Containers — Safely Using Sharps at Home, at Work and on Travel
- [5]Ayinde O, Hayward RS, Ross JDC. The effect of intramuscular injection technique on injection associated pain; a systematic review and meta-analysis. PLoS One 2021;16(5):e0250883
Next steps
Educational reference, not medical advice. Testosterone cypionate is a Schedule III controlled substance available on prescription only. Nothing here is an instruction to self-administer, and where the evidence does not support a step this page says so rather than filling the gap.