Common lip flip side effects include minor bruising, slight swelling, and brief altered lip sensation that resolve within 24-48 hours. Less common effects — usually only with aggressive dosing or imprecise placement — include slight smile asymmetry or temporary difficulty articulating specific sounds. The active medicine is botulinum toxin, prescribed in the UK by qualified clinicians after consultation.
Common side effects (most patients experience some of these)
Pinpoint bruising — resolves within 3-7 days, easily covered with makeup. Slight swelling — resolves within 24-48 hours. Brief altered sensation in the upper lip — settles within a few days. Slight tenderness at injection points. Subtle initial asymmetry as the effect develops, typically evening out by the two-week peak.
Less common side effects
Smile asymmetry beyond two weeks — usually a dose-and-placement issue, resolves as the medicine wears off (6-10 weeks). Temporary difficulty articulating specific sounds — patients needing precise lip articulation (wind instruments, singers) are screened carefully. Temporary difficulty drinking from a straw or pursing lips. A dropped or drooping lip line — usually a placement issue.
Rare side effects
Allergic reaction to medicine components — uncommon, screened by medical history. Infection at injection sites — uncommon with sterile technique. Distant spread of medicine — very rare at the small lip flip dose. Tissue damage from a vascular event — very rare with careful technique.
Reducing side-effect probability
Choose a clinician with prescriber status, formal training, and specific lip-flip experience. Be honest about medical history and expectations. Follow aftercare precisely — sleeping flat or facial massage in the first 24 hours can promote medicine migration. Use the two-week review to catch and adjust anything.
What to do if you experience a side effect
Common effects: watch and wait, cold compress helps. Less common effects: contact the clinic; the medicine wears off within 6-10 weeks regardless. Rare effects (allergic reaction, infection signs, breathing difficulty): seek urgent medical attention.
Frequently asked questions
Is a lip flip safe? With trained prescriber assessment and appropriate aftercare, the safety profile is strong; most side effects are minor.
How long do side effects last? Common effects 24-72 hours; less common effects resolve as the medicine wears off, typically 6-10 weeks.
Can it cause permanent damage? Very rare with qualified prescriber treatment — the effect is by mechanism temporary.
What side effects mean I should contact my clinic urgently? Signs of allergic reaction, infection, persistent asymmetry beyond two weeks, or vision changes.
Why are some patients more likely to get side effects? Dose, placement, clinician technique, and individual anatomy all play a part — choice of clinician is the largest factor patients can influence. The lip flip technique guide explains how placement is planned.
Information about consultation
Our anti-wrinkle treatment consultation is £65, redeemable in full against treatment. Call 020 8127 4567 or WhatsApp +44 7974 910222. Dental & Wellness London · 222 Essex Road, Islington, London N1 3AP.
Reviewed by Dr Vishal Patel · BDS Liverpool · MSc Aesthetic & Restorative Dentistry (Manchester) · GDC 103127 · AACD Member. Last reviewed 2026-06-05.
