Natural Factors Stress-Relax Melatonin 5 mg

Our assessment

The evidence shows: This product contains 5 mg of melatonin, but the available data focuses on calcium, not melatonin. For calcium, the data supports its role in bone mineralization and neuromuscular relaxation [NIH ODS]. However, we cannot make a specific assessment about the melatonin in this supplement because data on that ingredient is not available.

How it works

Regarding the calcium ingredient, think of it as a structural builder for your bones and a signal regulator for your nerves and muscles. It supports bone density and mineral deposition, while also helping your muscles relax and your nerves send proper signals [NIH ODS]. For the melatonin component, the specific mechanism of action for this product is not described in the provided data.

Safety profile

FDA has received a total of 592,059 adverse event reports across all supplements, though a specific count for this product is not available. For the calcium ingredient, side effects include constipation, nausea, weight loss, extreme tiredness, frequent need to urinate, and abnormal heart rhythms. High levels can also cause poor muscle tone, poor kidney function, and a high risk of death from heart disease [NIH ODS]. High calcium intakes might increase the risk of heart disease and prostate cancer [NIH ODS]. Calcium can reduce the absorption of medications including bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].

Our recommendation

Data for the melatonin ingredient is not available, so we cannot make a confident recommendation for this specific product. If you are considering calcium supplementation, be aware of the potential for side effects and interactions with medications [NIH ODS]. Consult your healthcare provider to determine if a calcium supplement is appropriate for you, and to discuss the risks of high calcium intake, including possible heart disease and prostate cancer [NIH ODS].

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