Why Sleep Experts Are Rethinking Melatonin

Over the past two decades, something striking has happened in bedrooms across the U.S. The use of the hormone melatonin has exploded. A new TIME article this week highlighted that adult usage has more than quintupled between 1999 and 2018. Meanwhile, pediatricians are now reporting that they rarely see a sleepless child whose parents haven’t at least tried melatonin.

Melatonin is often sold as a “natural sleep aid,” almost like a vitamin you take nightly to fix insomnia. But melatonin isn’t a vitamin. It’s a hormone. And for anyone who cares about performance, recovery, or energy, it’s important to understand how this hormone works, when it might make sense, and how it can quietly work against you over time.

This post breaks down how melatonin functions in the body, what the emerging concerns are, when it can be used strategically, and what smarter, safer alternatives exist.

What Melatonin Actually Does

Melatonin is produced by the pineal gland in the brain in response to darkness. Levels rise in the evening, peak in the early morning hours, and fall after sunrise. Its primary role isn’t to force you asleep like a sedative. Instead, it signals that nighttime has arrived and that the body should start shifting into rest and recovery mode.

In that role, melatonin helps coordinate many internal processes with the day-night cycle. Core body temperature drops, alertness declines, and systems like metabolism, hormone production, and immune regulation begin to transition toward nighttime function.

Think of melatonin more like a master timekeeper than a sleep trigger. For an athlete or performance-oriented sleeper, tampering with it regularly isn’t like taking a protein powder or magnesium supplement. Instead, you’re manipulating a hormonal signal that influences far more than just your sleep.

The Unseen Risks of Long-Term Use

One of the most concerning takeaways from the TIME article was a new report presented at the American Heart Association meeting. Researchers found that adults who had been taking melatonin for a year or longer had a 90% higher risk of heart failure compared to similar individuals who didn’t take it. That doesn’t prove melatonin caused the issue, but it raises an important red flag. As Harvard neurologist Dr. Tom Scammell notes, insomnia and heart disease often appear together, so melatonin may be a marker of underlying problems rather than the cause. Still, the correlation deserves attention.

In children, pediatricians are equally cautious. Melatonin influences more than sleep - it plays roles in bone growth, immune function, and reproductive hormone regulation. Long-term studies on these effects are limited, and no one yet knows what years of regular use could mean for development.

Even for adults, misuse and overuse are common. Since melatonin is sold over the counter in the U.S., it’s often treated casually, with many assuming that more is better. But it can linger in the body longer than expected, particularly for slow metabolizers, and excessive or poorly timed doses can actually make sleep timing worse, not better.

Why This Matters for Performance

For high performers, small mismatches in recovery physiology add up. When melatonin use overrides your body’s natural timing, the ripple effects can reach your nervous system, muscle repair, hormonal rhythms, and sleep architecture.

Poor timing or excessive use may shift your recovery window, reduce deep sleep (the phase when growth hormone surges), or delay your circadian reset the next day. These disruptions may be subtle but can impact performance, adaptation, and recovery over time.

If you’re chasing better performance, faster recovery, and deeper sleep, using melatonin nightly without a clear reason works against those goals.

When Melatonin Can Make Sense

Melatonin isn’t inherently bad - it’s just often misused. There are times when strategic, short-term use can be beneficial for athletes and working professionals.

1. Crossing Time Zones or Jet Lag

When you travel rapidly across multiple time zones, your internal clock falls out of sync with local time. In those cases, a small, well-timed dose of melatonin can act as a reset signal. Studies in athletes show that melatonin can help resynchronize circadian rhythm when used precisely and temporarily.

For example, athletes flying from the U.S. to Asia before competition sometimes take melatonin at a specific time relative to their target bedtime, helping their bodies adjust more quickly to local time. 

A few principles:

• Timing matters. The dose should align with when your body needs to shift in the new time zone, not when you simply want to fall asleep.
• Keep it short-term. A few nights at most, supported by light exposure, meal timing, and consistent wake times.
• Know the rules. Some governing bodies monitor supplement use, so competitive athletes should always check before adding it to a travel routine.

2. Schedule Shifts

If you have an early morning race or a late-night competition, melatonin may help you realign your sleep window temporarily.

Two-time Olympic gold medalist Natasha Hastings has said, “When I’m overseas, sometimes I’ll take some melatonin to help me fall asleep, especially when I’m trying to get adjusted to the time difference.” She also notes that depending on race timing, she may just keep her normal sleep pattern. The key insight is that melatonin is a tool, not a habit.

3. Specific Medical Conditions

Melatonin can be useful under medical supervision for certain conditions like circadian rhythm disorders, blindness, or in children with autism spectrum disorders. But these are exceptions, and should be consulted with a medical professional.  

Better Natural Alternatives for Deep, Consistent Sleep

For most people who train hard, recover intentionally, and aim for consistent nights of seven to nine hours, the smarter approach is to support, not override, your sleep physiology. That means consistent habits and targeted nutrients that calm the nervous system and prepare your body for natural rest.

Magnesium: Foundational Nervous-System Support

Magnesium is essential for hundreds of enzymatic reactions in the body. For sleep, it helps regulate the stress response (the HPA axis) and supports GABA activity, which promotes relaxation.

A 2024 randomized trial using magnesium L-threonate found improvements in both deep (N3) and REM sleep, along with better mood and daytime focus. Incorporating magnesium into your nightly routine helps your nervous system unwind naturally so your body can focus on true recovery instead of chemically induced sleep.

L-Theanine: Calming, Not Sedating

L-theanine, an amino acid found in tea leaves, promotes alpha-wave brain activity and boosts calming neurotransmitters like GABA and serotonin. When combined with magnesium, the two create a synergistic effect - easing mental tension and encouraging restorative sleep without manipulating hormonal timing.

Ashwagandha and Other Adaptogens

Adaptogens like ashwagandha help regulate the body’s stress response and improve sleep quality. They don’t act on melatonin pathways but complement the same goal—steady, restorative recovery.

The Night Bites Philosophy

At Lagoon, Night Bites were designed around this exact idea: support your nervous system and recovery, rather than hijack your sleep clock. Each serving includes 200 mg of magnesium and 200 mg of L-theanine to help your body wind down and prepare for meaningful sleep - without relying on hormones.

This kind of support builds long-term consistency, helping athletes recover better and maintain circadian rhythm over time.

How to Train Your Sleep Without Hormones

Quality sleep is built the same way fitness is: through structure, repetition, and smart routines. Here are the fundamentals:

• Stay consistent. Keep a steady wake time, even on weekends.
• Get morning light. Natural light within an hour of waking helps set your internal clock.
• Dim it down at night. Reduce bright light and screen exposure in the evening to allow natural melatonin release.
• Cool down. Lower your body temperature before bed with a warm shower and a cooler bedroom.
• Wind down. Prioritize quiet, low-stimulation activities - reading, stretching, or journaling - over intense physical or mental effort.
• Plan for travel. Adjust bedtime and light exposure in the days leading up to trips or competitions.

If your sleep habits are inconsistent, taking melatonin nightly is like relying on a crutch instead of rebuilding your strength.

Reclaiming Natural Sleep

When melatonin it’s used nightly, without context or guidance, it’s often a symptom of a deeper rhythm problem. If you’re reaching for it every night, ask yourself whether your body is truly deficient in melatonin, or if your habits are simply out of sync with your biology.

For most high performers, the answer is simple:

• Save melatonin for travel or schedule shifts.
• Build your foundation with magnesium, L-theanine, and strong sleep hygiene.

Remember that optimizing your sleep means respecting your biology, aligning your rhythm, and supporting your body’s natural ability to recover.