Melatonin

Appearance: White to off-white crystalline powder

Solubility: Very slightly soluble in water and dilute hydrochloric acid; soluble in ethanol (at least 50 mg/mL)

Melting point: 116.5°C to 118°C

Melatonin supplements contain very low to negligible calories and macronutrients. For example, a popular melatonin supplement brand shows about 0.05 kcal per serving, with nearly 0 grams of fat, carbohydrates, and protein.

The benefits of melatonin primarily relate to its role in regulating the sleep-wake cycle and improving sleep quality. Key benefits include:

• Improved sleep duration and quality: Melatonin supplements can help increase total sleep time and reduce the time it takes to fall asleep, especially for people with insomnia or sleep difficulties.

• Circadian rhythm regulation: Melatonin helps synchronize the body’s internal clock with day-night cycles, aiding those with disrupted rhythms due to shift work, jet lag, or certain sleep disorders.

• Support for sleep disorders: Supplementary melatonin may benefit people with circadian rhythm disorders like non-24-hour sleep-wake rhythm disorder and delayed sleep phase disorder by helping to align sleep timing.

• Enhances restorative sleep: Melatonin promotes sleep anticipation in the brain and may improve the restorative value of sleep, which can aid in better daytime functioning and cognitive health.

• Additional health effects: Melatonin’s antioxidant properties may contribute to eye health, reduce symptoms of acid reflux and tinnitus, alleviate migraine pain, and potentially support brain health in conditions like Alzheimer’s disease.

• Regulation of various physiological functions: Melatonin influences blood pressure, body temperature, glucose metabolism, hormone levels, and more, tying its role to overall circadian physiology.