Primary and secondary
A primary anaesthetic (commonly 5% lidocaine, sometimes with prilocaine/benzocaine/tetracaine blends) is applied to intact lips under occlusion for 20–40 minutes before starting. Once the skin is broken, a secondary gel that also contains epinephrine can be used: it penetrates the micro-wounds fast and its vasoconstriction reduces bleeding and swelling.
Using them safely
Follow the product's maximum quantity and contact time — lidocaine toxicity is real if huge amounts are used on broken skin. Epinephrine-containing products are avoided or used with caution in people with uncontrolled hypertension, cardiac arrhythmia, hyperthyroidism, phaeochromocytoma, or on certain medications, and in pregnancy.
Ask about 'caine' allergies (true amide-lidocaine allergy is rare but ester-type is not), and about latex, adhesives and prior reactions.
Realistic comfort
Numbing makes lip blushing tolerable for the large majority — a buzzing, scratchy pressure rather than sharp pain — but it wears unevenly, works less well on inflamed tissue, and the corners and cupid's bow stay sensitive. 'Completely painless' is not a promise to make.
Regulatory note
Who may apply which strength of anaesthetic, and whether epinephrine blends are permitted for non-medical artists, varies by country and state. Use only products legal for your scope where you practise.
