Nov 9, 2025
The Study:
A November 2025 analysis of 130,000+ adults found that people taking melatonin long-term had:
89% higher risk of heart failure
2x higher risk of death from any cause
3.5x higher hospitalization rate for heart failure
Melatonin is the 4th most popular supplement in the US, sold over-the-counter with zero medical supervision. While it's safe for short-term use (1-2 months), there's virtually no research on long-term safety.
Concern
Millions take melatonin for months or years without knowing the cardiovascular risks. The research is preliminary, but serious enough that doctors are reconsidering how they recommend sleep aids.
The Better Alternative: Magnesium + L-Theanine
This combination is science-backed, safe long-term, and actually supports heart health.
Magnesium Threonate (145 mg) or Bisglycinate (300–400 mg)
Crosses blood-brain barrier for deeper sleep
Reduces racing thoughts and anxiety
Supports cardiovascular health (opposite of melatonin)
L-Theanine (100–400 mg)
Promotes calm, relaxed brain state
Enhances natural sleep neurotransmitters
No grogginess
Timing: Take 30-60 minutes before bed
Melatonin | Magnesium + L-Theanine |
|---|---|
Heart risks | Supports heart health |
Forced sleep | Works with your biology |
Tolerance builds | Gets better with time |
Limited safety data | Thousands of studies |
No long-term benefit | Safe indefinitely |
Conclusion
The melatonin study signals a critical shift in how we should think about sleep supplements. If you've been taking melatonin long-term, switching to magnesium + L-theanine is a smarter choice since it works better and won't put your heart at risk.
Talk to your doctor, make the switch, and experience genuinely restorative sleep.
If you want to make more science based lifestyle choices download the pom app, which shows you research on anything with an ingredients label:
App Store: https://apps.apple.com/ca/app/pom-ingredient-checker/id6737084514?ct=blog_mel
Play Store: https://play.google.com/store/apps/details?id=app.thepom&referrer=utm_source%3Dblog%26utm_campaign%3Dmel
Citations
Nnadi, E., et al. "Long-term Melatonin Supplementation and Risk of Heart Failure." American Heart Association Scientific Sessions, November 2025. (Preliminary study, not yet peer-reviewed)
Hausenblas, H.A., et al. "Magnesium-L-threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems: A randomized controlled trial." Sleep Medicine X, 8:100121, 2024.
Abbasi, B., et al. "Effect of magnesium supplementation on sleep quality: A randomized, placebo-controlled trial." Journal of Research in Medical Sciences, 17(2), 161-169, 2012.
Kim, S., Jo, K., et al. "GABA and l-theanine mixture decreases sleep latency and improves NREM sleep." Pharmacology & Biology, 57(1), 65-73, 2019.
Jang, H.S., et al. "L-theanine partially recovers PC12 cell death induced by H2O2." Phytotherapy Research, 22(6), 778-785, 2008.
FAQ
Q: Is melatonin dangerous? A: The research shows a strong association with heart failure for long-term use. It's safe for 1-2 months, but chronic use lacks safety data. Switching to alternatives is the smarter move.
Q: Can I stop melatonin immediately? A: Yes, melatonin doesn't create dependence. Switch to the magnesium + L-theanine stack at the same time to maintain sleep quality.
Q: How fast does the stack work? A: Most people notice improvement within 3-7 days. Give it 2-3 weeks for full effectiveness.
Q: Is it safe to take every night? A: Yes. Unlike melatonin, it's safe long-term and actually works better with consistent use.
Q: Threonate vs. Bisglycinate? A: Threonate crosses the blood-brain barrier better. Bisglycinate is easier on digestion. Both work for sleep.
Q: Should I take with food? A: Magnesium absorbs better with food. Take both 30-60 minutes before bed.
Q: Drug interactions? A: Generally safe, but check with your doctor if you're on blood thinners, bisphosphonates, or antibiotics.
Q: Safe during pregnancy? A: Consult your doctor before starting any supplement while pregnant or breastfeeding.
Q: Can I mix with alcohol? A: No. Both are sedative. Wait 3-4 hours after drinking before taking the stack.