Can Wegovy injection cause bruising, and how can it be prevented?

Small bruises can happen — they’re usually harmless. Prevent them by rotating sites, using a new needle every time, injecting at 90° into the fatty layer, and holding gentle pressure (don’t rub) for 10–20 seconds. Pick a site without visible veins, and avoid areas that are sore or recently exercised. If you’re on blood thinners or bruise easily, mention this to your team; technique tweaks can help.

Why bruising sometimes happens

Bruising after an injection occurs when a tiny blood vessel under the skin is nicked by the needle. It’s a routine possibility with subcutaneous medicines and not unique to Wegovy. A small amount of blood can leak into the tissue, forming a mild, temporary mark that’s tender for a day or two but medically insignificant. NICE TA875 and NHS patient materials note that redness, itching, or mild bruising are common early reactions. These marks don’t affect how the medicine works and usually fade within a week.

Injection technique and site selection

Good technique makes a big difference. NHS guidance for GLP-1 injections advises inserting the needle straight (at 90°) into the fatty layer of the abdomen, thigh, or upper arm — never into muscle. Choose an area that feels soft when pinched lightly, avoiding veins, scars, or hard lumps. Always use a new sterile needle: reusing one dulls the tip and tears tissue, making bruises more likely. The MHRA also advises single use to prevent blunting and contamination.

After injecting, hold gentle pressure with a clean finger or tissue for 10–20 seconds to stop small bleeds under the skin. Rubbing spreads the blood, enlarging the bruise, so simply press and wait. If a drop of blood appears, wipe it away gently. NICE and NHS training both reinforce that pressure — not massage — is best for keeping marks small.

The role of site rotation

Injecting repeatedly in the same area can irritate tissue, causing both bruising and small lumps (lipohypertrophy) that reduce absorption. Rotating sites weekly protects skin health. Stay within the same general region — such as the abdomen — but move at least a finger’s width from the last injection. Many patients use a rotation pattern like top right, lower right, top left, lower left, then repeat. NHS nurses often provide diagrams to help you vary placement and track sites easily.

Factors that make bruising more likely

People who bruise easily, have fair or thin skin, or use anticoagulants such as warfarin or aspirin may see marks more often. NICE and MHRA guidance recommend telling your clinician if you take blood thinners, as pressing slightly longer or choosing the abdomen can reduce bruising risk. Avoid injecting into recently exercised or sore areas, where blood flow is higher. Temperature also plays a role: warm skin brings vessels closer to the surface. Waiting 10–15 minutes after a shower or applying a cool pack for a few seconds afterward helps minimise marks. NHS clinicians describe these as “small, smart adjustments” that make injections more predictable.

When to seek advice

Most bruises are harmless, but contact your healthcare team if one becomes large, painful, or lasts more than two weeks, or if the area turns red, swollen, or hot. These signs may indicate irritation or infection rather than a simple bruise. People on blood thinners or with clotting disorders should also report unexpected bruising early. MHRA and NHS safety alerts stress that ongoing skin checks maintain confidence and help identify rare complications promptly.

Everyday habits that help

Keeping pens and needles at room temperature before use prevents cold metal from shocking the skin. Clean the area with mild soap or an alcohol swab, letting it dry fully before injecting. Insert and remove the needle smoothly rather than forcefully. Using a different part of the body each week gives previous sites time to heal. Some people find that standing relaxes abdominal skin and makes bruising less frequent; others prefer sitting for a steady angle. Either method works as long as it feels comfortable and stable.

Support and reassurance from the NHS

NICE TA875 and NHS England’s 2025 implementation framework both highlight that confidence in self-injection grows with experience and good guidance. Bruising is one of the most common topics raised in follow-up calls. Clinics and pharmacies can review technique, demonstrate angles that suit different body types, or recommend slightly longer or shorter needles where appropriate. NICE guidance reassures patients that mild bruising is not a sign of error — and that it often decreases as technique becomes automatic.

Looking at the whole story

Bruising from Wegovy injections is common, mild, and easy to prevent. It happens when a small surface vessel is touched by the needle and clears within days. Rotating sites, using fresh needles, injecting at 90°, and pressing gently afterwards all minimise marks. NICE, NHS, and MHRA guidance agree: good technique and consistent practice make treatment safer and more comfortable. Looking at the whole story, these small steps help keep your skin healthy, your confidence steady, and your routine smooth — making each injection just another simple part of the week.