Product Label

21st Century Melatonin 5 mg

Brand: 21st Century · Form: TABLET [E0155] On Market

Our assessment

The evidence shows that 21st Century Melatonin 5 mg is a supplement intended to support sleep, but you should be aware of significant data limitations. While the product contains melatonin, the provided data focuses on calcium, not melatonin. For this specific product, key information on how it works and its safety profile is incomplete. You should always consult a healthcare provider before starting any new supplement, especially for sleep.

How it works

Based on the data provided for calcium, this ingredient supports bone mineralization by aiding bone density and mineral deposition, and it also supports neuromuscular relaxation by aiding muscle relaxation and nerve signaling [NIH ODS]. Data on how melatonin specifically works is not available.

Safety profile

The FDA received a total of 592,059 adverse event reports across all supplements, but specific report counts for this product or its melatonin ingredient are not available. Side effects listed are for calcium, not melatonin. High levels of calcium can cause constipation, nausea, weight loss, extreme tiredness, frequent need to urinate, and abnormal heart rhythms [NIH ODS]. Calcium can also reduce the absorption of medications like bisphosphonates, tetracycline antibiotics, and levothyroxine [NIH ODS]. Side effects for melatonin are not available in the provided data.

Our recommendation

Because the provided safety and efficacy data pertains to calcium rather than melatonin, we cannot make a confident recommendation for 21st Century Melatonin 5 mg. For sleep support, you should seek products with clear, product-specific data. Always start with the lowest effective dose and discuss any supplement use with your doctor or pharmacist, especially if you take other medications [NIH ODS].

AI-assisted analysis. Data sourced from NIH DSLD.

Supplement Facts

Brand21st Century
Serving Size
Contents120.0 Tablet(s)
Market StatusOn Market

How to Read This Label

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

Original Label

View Full DSLD Label (PDF)

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