Can I use lip balm while fasting?

Why it's allowed

The fast is broken by things that deliberately go down your throat, such as food, drink or anything swallowed. Lip balm stays on the outside of your lips. Scholars of all four schools (Hanafi, Maliki, Shafi'i, Hanbali) treat creams and ointments on the skin as not breaking the fast, and lips are part of that. Dry, cracked lips are very common during long fasts and cold European winters, so this is a real need.

The one thing to watch: swallowing

• Don't lick your lips right after applying it.
• Use a thin layer, so it doesn't run into your mouth.
• If you taste it, spit. A faint taste on your lips is fine; what matters is not swallowing it on purpose.
• Accidental traces that you couldn't avoid don't ruin your fast, much like everyday saliva. See Does swallowing my spit break my fast?

Flavoured balms and lipstick

Flavoured or sweet balms are still allowed, but some scholars call them disliked (makruh) while fasting, because the flavour tempts you to lick and taste. An unflavoured balm or plain petroleum jelly is the easiest choice. The same rules apply to lipstick and lip gloss: they don't break the fast, but don't swallow them. If you'd like to understand a similar case, see Can I chew gum while fasting? (that one is different, because gum releases flavour into your mouth).

Other skin products

Moisturiser, sunscreen, hand cream and deodorant don't break the fast either, for the same reason. See Can I wear deodorant while fasting? Medicated balms for cold sores work the same way, as long as you don't swallow them. If you need lip balm, use it without worry. Islam doesn't want your fast to be harder than it needs to be.