Does Caffeine Affect Melatonin?

Amount or timing may matter

The short answer

Caffeine directly opposes melatonin's sleep-inducing effect and delays circadian rhythm.

How to arrange timing

Avoid caffeine at least 6 hours before taking melatonin.

Reference

Reference noted for this food and supplement combination: NIH ODS 2024

Important context

The effect can also change with food amount, supplement dose, product formulation, health conditions, and medication use. Ask a doctor or pharmacist first if you take medication, are pregnant or breastfeeding, or have a chronic condition.