The safe amount of melatonin varies by age and individual factors, but general guidelines are as follows:

• Adults: Most adults can start with 1 mg of melatonin about 30 minutes before bedtime and increase by 1 mg weekly if needed, not exceeding 10 mg at a time. Typical effective doses range from 1 to 5 mg. Doses above 10 mg are generally not recommended and may cause side effects such as headache, dizziness, nausea, and daytime drowsiness. Very high doses (e.g., 30 mg) are considered unsafe by most experts and can worsen sleep problems

• Children: For children under 88 pounds, a maximum dose of 3 mg per dose is recommended, while children and teens over 88 pounds can take up to 5 mg at once. Melatonin use in children should be approached cautiously and under medical supervision due to potential hormonal effects and limited research on long-term safety

• Older adults: Older adults should consult a doctor before using melatonin and generally use the lowest effective dose for a short duration, as melatonin may stay longer in their system and cause daytime lethargy

• General advice: Start with the lowest dose possible to minimize side effects and increase gradually if needed. Because melatonin supplements are not FDA-regulated for purity and dosage accuracy, it is important to purchase from reputable sources and consult a healthcare provider before starting supplementation, especially for children, older adults, pregnant or nursing women, or those on medications

In summary, a safe adult dose is typically between 1 and 5 mg, not exceeding 10 mg, while children should take lower doses based on weight and age, and medical advice is recommended for all groups before use.