Which supplement is used for sleep and insomnia?

• A. Garlic
• B. St. John's Wort
• C. Melatonin
• D. Echinacea

Answer: (C)

Melatonin helps regulate the body’s internal clock, signaling to the brain when it’s time to sleep. As a supplement, it’s used to treat sleep-onset insomnia and circadian rhythm sleep disorders (like jet lag or shift-work sleep disruption) by helping to realign the sleep-wake cycle. It’s not a sedative; the effect is best when taken at the right time, usually a low dose such as 0.5–3 mg about 30–60 minutes before bedtime. Side effects are typically mild, like morning grogginess or headaches, and it’s generally used for short-term sleep support. The other substances listed aren’t aimed at improving sleep—garlic is for cardiovascular/immune benefits, St. John’s Wort is used for mood and interacts with many drugs, and echinacea is mainly for immune support. So, melatonin is the supplement most directly linked to sleep and insomnia.