For a standard intramuscular injection, you do not pinch the skin. Pinching, or “bunching,” lifts the subcutaneous fat layer away from the underlying muscle, which is the opposite of what you want when the goal is to deposit medication deep into muscle tissue. The technique most clinicians use instead is to stretch the skin flat at the injection site or to use a displacement method called the Z-track technique. That said, there are narrow exceptions where a pinch does help, and the reasoning behind both approaches is worth understanding if you give or receive IM injections regularly.
Why Pinching Works Against You in an IM Injection
The whole point of an intramuscular injection is to get the needle tip past the skin and the layer of fat beneath it, and into the belly of the muscle. Pinching the skin bunches subcutaneous tissue upward, effectively thickening the barrier the needle has to cross before reaching muscle. Ultrasound imaging in children and adolescents showed that pinching the abdominal skin fold nearly tripled the subcutaneous fat thickness (an increase of about 192%), and even pinching at the thigh increased it by roughly 22%. In very lean individuals, pinching at the thigh actually compressed the fat layer so much that it reduced subcutaneous thickness, but that is the exception rather than the rule.
This matters because a significant share of IM injections that are intended for muscle end up in fat instead. A systematic review found that dorsogluteal injections frequently land in subcutaneous tissue rather than muscle, particularly in people with a body mass index above 25 and especially in women.
1PubMed. Dorsogluteal intramuscular injection depth needed to reach muscle tissue according to body mass index and gender: A systematic reviewAdding a pinch on top of an already-thick fat layer only makes this problem worse. This is why clinical guidelines for IM injections consistently instruct the provider to flatten or stretch the skin rather than gather it up.
What Providers Do Instead
Two skin-handling techniques dominate modern IM injection practice: the flat stretch and the Z-track.
The flat stretch is exactly what it sounds like. You spread the skin taut between your thumb and forefinger at the injection site, then insert the needle at a 90-degree angle. Stretching the skin serves two purposes: it anchors the tissue so the needle enters cleanly, and it pulls the subcutaneous layer thinner, shortening the distance to muscle.
The Z-track technique takes things a step further. Before inserting the needle, you use the side of your non-dominant hand to pull the skin and subcutaneous tissue laterally, displacing it to one side. You then insert the needle, inject the medication, withdraw the needle, and release the skin. When the tissue slides back to its original position, the entry path through the skin no longer lines up with the deposit of medication in the muscle. This creates a zigzag seal that helps prevent the drug from leaking back along the needle track and onto the skin or into the subcutaneous layer.
Research supports the Z-track method for reducing drug leakage. A randomized controlled trial of intramuscular diclofenac sodium found that the Z-track group had less leakage at the injection site compared to a standard technique group.
2PubMed. The Effect of the Z-Track Technique on Pain and Drug Leakage in Intramuscular InjectionsAnother trial, this one involving intramuscular magnesium sulfate for severe pre-eclampsia, found the Z-track group experienced less pain at later injections, less drug leakage, and less inflammation at the injection site compared to the standard approach.
3International Journal of Research in Medical Sciences. Z-track technique reduces pain at the injection site, drug leakage, post-injection gluteal inflammation in Pritchard regimen for severe pre-eclamptic patients: findings from a randomized controlled trialThe One Scenario Where Pinching Might Help with an IM Injection
Very thin patients, particularly infants and young children, sometimes have so little subcutaneous tissue that the opposite problem arises: the needle could pass through the muscle entirely and hit bone or periosteum. In these cases, gently bunching the muscle mass between the fingers can help ensure the needle stays within the target tissue. Some pediatric guidelines describe this for the vastus lateralis (the outer thigh muscle used for infant vaccinations), where the provider grasps the muscle belly itself rather than just pinching superficial skin. The distinction matters: you are compressing muscle upward toward the needle, not lifting a fat layer away from it.
For adults with normal or above-average subcutaneous tissue, this scenario does not apply, and pinching would simply push the muscle further from the needle tip.
But Does Pinching Reduce Pain?
Here is where things get interesting, because pinching the skin before or during a needle stick can genuinely reduce how much pain the person feels. A randomized trial of 78 women receiving intramuscular Depo-Provera injections in the gluteal region compared a “pinch technique” group with a standard injection group. Only about 15% of the pinch group reported severe pain, compared to roughly 38% of the standard-injection group, a statistically significant difference.
4PubMed. Painless Depo-medroxyprogesterone acetate (DMPA) injections using the ‘pinch technique’The idea behind this rests on gate control theory: strong, non-painful sensory input (like pressure from a pinch) can partially “close the gate” on pain signals traveling along smaller nerve fibers. In plain terms, the brain pays more attention to the pinch than to the needle, so the stick hurts less.
So you have a genuine tension. Pinching can lower pain, but it can also push the medication into the wrong tissue layer. In that Depo-Provera trial, this trade-off was less critical because the drug is a depot injection designed for slow release, and the gluteal site has relatively thick muscle in most patients. For vaccines and other drugs where landing in muscle matters for absorption and efficacy, the pain-reduction benefit of a pinch does not outweigh the risk of a misplaced injection.
Other Ways to Manage Injection Pain Without Compromising Depth
If pinching is off the table for a standard IM injection, what can you do about pain? Quite a lot, it turns out, and the evidence is surprisingly robust for several alternatives.
A systematic review and meta-analysis of injection technique studies found that applying manual pressure to the site before the injection reduced pain, with a moderate effect size. Helfer skin tapping, a rhythmic tapping on the skin around the injection site, showed an even larger pain reduction.
5PubMed Central. The effect of intramuscular injection technique on injection associated pain; a systematic review and meta-analysisAcupressure techniques involving sustained pressure followed by intermittent tapping near the injection site also reduced pain across multiple studies.
Another systematic review confirmed that pinch technique, manual pressure, and massage all reduced pain compared to standard treatment or no intervention in adults receiving IM injections.
6JBI Evidence Synthesis. Effectiveness of physical stimulation for reducing injection pain in adults receiving intramuscular injections: a systematic review and meta-analysisIn children specifically, a randomized trial found that both vibration and manual pressure applied during IM injections significantly reduced pain, anxiety, and fear in kids aged five to ten.
7PubMed. The effects of vibration and pressure interventions on children’s pain, fear and anxiety: A randomized controlled trialThe practical takeaway is that you can get pain relief from pressure-based methods that do not involve lifting tissue away from the muscle. Firm pressure applied with a finger or thumb for several seconds before the injection, or vibration from a device placed near the site, both activate those same competing sensory pathways without changing the injection’s depth. Some clinics use small vibrating devices placed adjacent to the injection site for exactly this reason.
Why Getting the Depth Right Matters More Than You Might Think
Some people assume that whether a medication lands in muscle or in the fat just above it is a minor detail. For certain drugs, it is not minor at all. The subcutaneous fat layer acts as a kind of slow-release depot for lipophilic (fat-loving) drugs, and absorption times from fat are considerably longer than from muscle for many formulations.
8International Journal of Pharmaceutics. Release and absorption rate aspects of intramuscularly injected pharmaceuticalsA drug that should reach the bloodstream in minutes when injected into muscle might take much longer when it sits in fat. For vaccines, an injection that stays in subcutaneous tissue may produce a different immune response than one delivered to muscle, which is why vaccination guidelines specify IM delivery at particular sites.
At the extreme end, poor injection technique can lead to serious complications. Nicolau syndrome is a rare but dramatic example: tissue death at the injection site caused by medication landing in fat rather than muscle. A case series linked this complication to misplaced gluteal injections where the subcutaneous fat layer was extremely thick and the standard needle was too short to reach muscle.
9PubMed Central. Nicolau syndrome after intramuscular injection of non-steroidal anti-inflammatory drugs (NSAID)These cases are uncommon, but they underscore why technique details like skin handling, needle length, and site selection are not just academic concerns.
Choosing the Right Site
Where you give the injection matters as much as how you handle the skin. The deltoid (upper arm) is the most common site for vaccines in adults, while the vastus lateralis (outer thigh) is preferred for infants and young children because the thigh muscle is the largest available muscle mass at that age. The ventrogluteal site (the hip) is increasingly recommended for larger-volume IM injections because it has a thinner fat layer and fewer major blood vessels than the traditional dorsogluteal (upper outer buttock) site.
A cadaver and imaging study confirmed that the middle of the vastus lateralis is a safe injection site because of the low risk of hitting a major blood vessel or nerve.
10PubMed Central. Anatomically safe sites for intramuscular injections: a cross-sectional study on young adults and cadavers with a focus on the thighThe dorsogluteal site, by contrast, is the one most associated with inadvertent subcutaneous injection because the fat layer there tends to be thickest. If you or your provider are concerned about reaching muscle, choosing the ventrogluteal or deltoid site is a more reliable fix than adjusting how you handle the skin.
Aspiration Has Also Fallen Out of Favor
While we are on the topic of outdated IM injection practices, aspiration, the step where you pull back on the syringe plunger before injecting to check for blood, has also been largely abandoned. A systematic review concluded that aspiration during intramuscular injection is unnecessary in pediatric vaccination and that there is no clinical reason this finding should not extend to the deltoid, ventrogluteal, and vastus lateralis sites in other settings.
11PubMed. Aspirating during the intramuscular injection procedure: a systematic literature reviewThe rationale is straightforward: the recommended IM injection sites do not have large blood vessels that a standard-gauge needle would enter, and the aspiration step prolongs contact between the needle and the tissue, increasing pain. Many nurses were taught to aspirate as students and continue the habit, but current evidence-based guidelines advise dropping it.
If you receive an IM injection and notice the provider does not pull back on the plunger, that is not a shortcut. It reflects updated practice.
The Needlestick Risk of Pinching
There is one more reason pinching has fallen out of favor for injections in general, and it has nothing to do with the patient. Pinching puts the provider’s non-dominant hand directly in the path of the needle. An analysis of bilateral exposure injuries, where the needle passes through the patient’s tissue and into the provider’s finger on the other side, found that manually elevating (pinching) subcutaneous tissue before injection was one of the strongest predictors of this type of needlestick injury. The study identified seven factors that together explained about 65% of the variation in bilateral exposure injuries, and pinching was among them alongside thin or emaciated patients and specific drug types.
12PubMed. Ditch the pinch: bilateral exposure injuries during subcutaneous injectionThe title of that study, “Ditch the Pinch,” has become something of a catchphrase in nursing safety circles. Even for subcutaneous injections where pinching has traditionally been standard, many institutions now recommend alternatives like using shorter needles with an angled insertion instead. For IM injections, where pinching was never the recommended technique in the first place, the occupational safety data only reinforces the case for stretching or Z-tracking instead.
Subcutaneous Versus Intramuscular Confusion
Much of the confusion around pinching stems from mixing up subcutaneous and intramuscular technique. Subcutaneous injections, such as insulin and many anticoagulants, go into the fat layer just beneath the skin. Pinching a skin fold for these injections is a long-established way to isolate that fat layer, prevent the needle from going too deep, and ensure the drug stays in subcutaneous tissue. You insert the needle at a 45-degree angle into the raised fold of skin and fat.
Intramuscular injections require the opposite approach. You want to bypass that fat layer entirely. The needle goes in at 90 degrees, and you stretch the skin flat to minimize the distance to muscle. If someone teaches you to “pinch and inject,” ask what type of injection they are describing. The answer determines whether the pinch is correct or counterproductive.
Self-injectors who switch between subcutaneous and intramuscular medications sometimes carry the pinching habit from one to the other. If you give yourself both types of injection, the simplest rule of thumb: subcutaneous gets a pinch and a 45-degree angle; intramuscular gets a stretch and 90 degrees. The exceptions, like very lean patients, are narrow enough that a healthcare provider would flag them for you individually.