Natural Factors Stress-Relax Melatonin 1 mg

Our assessment

The evidence shows that calcium is a critical mineral for bone health, but it comes with important safety considerations. For the product Natural Factors Stress-Relax Melatonin 1 mg, the active ingredient is melatonin, not calcium. Data for calcium is provided for general reference, but it does not apply directly to this product. The key takeaway: this supplement is designed for sleep support, not mineral replacement.

How it works

Calcium supports bone mineralization by helping deposit minerals into your skeleton, and it aids neuromuscular relaxation by supporting muscle relaxation and nerve signaling [NIH ODS]. However, for this specific product, melatonin is the active ingredient—it works by helping regulate your sleep-wake cycle. You should not rely on this product to meet your calcium needs.

Safety profile

FDA received a total of 592,059 adverse event reports across all supplement categories. For calcium specifically, high intakes may increase the risk of heart disease and prostate cancer [NIH ODS]. High blood and urine calcium levels can cause poor muscle tone, poor kidney function, low phosphate levels, constipation, nausea, weight loss, extreme tiredness, frequent urination, abnormal heart rhythms, and a high risk of death from heart disease [NIH ODS]. Calcium can also reduce absorption of medications including bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].

Our recommendation

If you are taking Natural Factors Stress-Relax Melatonin 1 mg for sleep, do not use it as a calcium source—it does not contain calcium. For bone health, get calcium from food or a dedicated calcium supplement, but keep total intake within safe limits. Always check with your pharmacist about interactions with your medications [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