A small bump or pinkness at the injection site is normal. Here's what's not.

Normal

Small (1–2 cm) area of mild redness, slight itch, small bruise. Resolves in 1–3 days.

Try a different site

Rotate among abdomen, upper thigh, upper arm. Stay 2 cm away from previous sites for a week. Don't inject through skin that's already irritated.

Concerning

Spreading redness, warm to touch, increasing pain over 24 hours — possible infection, rare but real. Hard lump that doesn't resolve in a week — message us.

Severe allergic reaction

Swelling of face, throat, difficulty breathing — emergency. Stop using the pen, call 112 or get to a hospital.