Viper's Kiss

You imbue a weapon or up to three pieces of ammunition with venom. The next time an affected weapon hits a creature before the spell ends, the attack deals an extra 1d6 poison damage, and the target must succeed on a Constitution saving throw or become poisoned until the start of your next turn.

The spell then ends on that weapon or piece of ammunition. The venom is harmless to you.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the poison damage increases by 1d6 for every two slot levels above 1st.