Sundown Melatonin 300 mcg

Our assessment

The evidence shows that Sundown Melatonin 300 mcg is a very low-dose supplement. For context, the primary ingredient listed is Calcium, not melatonin, based on the data provided. Data not available for melatonin-specific effects or dosing. For calcium, our assessment is that 300 mcg of calcium is a negligible amount—far below the recommended daily allowance—and would not provide meaningful bone health benefits [NIH ODS].

How it works

Think of calcium as a master regulator for your bones and nerves. It supports bone mineralization and density, and it helps your muscles relax and your nerves signal properly [NIH ODS]. However, the 300 mcg dose in this product is extremely small; for reference, the typical calcium supplement provides 500–1,000 mg (which is 500,000 to 1,000,000 mcg). This product would not provide a measurable effect on bone health or neuromuscular function.

Safety profile

FDA has received 592,059 total adverse event reports across all supplements, but specific report counts for this product are not available. For calcium specifically, very high intakes can cause constipation, nausea, poor muscle tone, abnormal heart rhythms, and a high risk of death from heart disease [NIH ODS]. At 300 mcg, however, this product is far below any level of concern for these side effects. Calcium can also reduce absorption of medications like bisphosphonates, tetracycline antibiotics, and levothyroxine [NIH ODS].

Our recommendation

Start by checking your calcium needs with a healthcare provider. This product’s 300 mcg dose is too low to meet daily requirements, which are typically 1,000–1,200 mg (1,000,000–1,200,000 mcg) for adults [NIH ODS]. If you need calcium, choose a standard 500–600 mg supplement and take it separately from other medications. Data not available for melatonin content or effects in this product.

Supplement labels contain several key sections regulated by the FDA:

• Serving Size — The recommended amount per dose. Always check this — some products require multiple capsules per serving.
• Amount Per Serving — Shows the quantity of each nutrient in the product, typically in IU (International Units), mg (milligrams), or mcg (micrograms).
• % Daily Value (%DV) — Indicates how much a nutrient in a serving contributes to a daily diet. 5% DV or less is low; 20% DV or more is high.
• Other Ingredients — Lists inactive ingredients like fillers, binders, and capsule materials (e.g., gelatin, cellulose, magnesium stearate).
• Suggested Use — The manufacturer's recommended directions for taking the supplement, including timing and dosage.

Source: FDA Dietary Supplement Labeling Guide