When taken appropriately, melatonin is generally considered safe. Symptoms include drowsiness, headaches, and dizziness, which usually go away on their own after a short period.
There is, however, still a lot more research needed to fully understand the potential uses and benefits of melatonin, as it has not been approved by the FDA for treating any medical condition.
Overdosing on melatonin can cause headaches, dizziness, and nausea. Also, it is important to be aware that melatonin may interact with certain medications and may not be safe for everyone. Blood thinners, blood pressure medications, and diabetes medications may interact with melatonin, for example.
Sometimes if needed I take an extra one just before bed.