How Bad Is It Really to Take Melatonin Every Night?

Taking melatonin can help you get through a short stretch of lousy sleep or get better rest when you're jet lagged. But is it a problem if the supplement has become a part of your standard nighttime routine?

Melatonin is generally safe for short-term use, though for some people, it can cause mild side effects. But it's not recommended for managing chronic or long-term insomnia, according to the National Center for Complementary and Integrative Health (NCCIH).

"There's a lack of convincing evidence regarding its effectiveness and safety profile, and it has shown mixed efficacy in trials," says Kunal Kumar, MD, the medical director of the Sleep Center at Einstein Medical Center Philadelphia.

Here's a look at why experts warn against making melatonin a regular part of your sleep routine and how to use it safely when you need it.

Experts typically recommend taking melatonin for short stretches when you're having trouble sleeping. "It appears to be safe to take melatonin for four to eight weeks," Dr. Kumar says. But long-term use hasn't been well-studied, so it's hard to say for sure what might happen if you take it for extended periods.

That said, here are some likely possibilities:

Melatonin isn't an addictive substance, so you can't actually get hooked on it. But if you get into the habit of taking it every night, you might start to convince yourself that you can't sleep without it.

"Any non-habit forming agent or ritual used routinely for sleep onset may have a psychological basis, as patients may feel dependent upon its usage," says Thomas Yadegar, MD, a pulmonary, critical care and sleep specialist at Providence Cedars-Sinai Tarzana Medical Center in Los Angeles.

Melatonin is meant to be a temporary solution for short-term sleep issues. So if it hasn't helped after several weeks, you could actually have a chronic sleep problem that isn't being addressed — like sleep apnea.

"Underlying sleep disorders, particularly when symptoms last longer than three months or impact activities of daily living, should be promptly evaluated by a medical professional," Dr. Yadegar says.

Melatonin, though generally considered safe, can cause headache, dizziness, nausea, drowsiness, anxiety, irritability or depression, according to the Mayo Clinic. If you get hit with these side effects after taking the supplement once or twice, there's a good chance you'll experience them regularly from taking melatonin every night.

Melatonin can interact with a number of prescription medications. For instance, it can increase the risk of bleeding for people who take anticoagulants or antiplatelet drugs, make anti-seizure medications less effective, or alter blood sugar in people taking diabetes medications, per the Mayo Clinic. Over time, that could have a negative impact on your health.

You should talk with your doctor before using melatonin (for short- or long-term use) if you take:

• Anticoagulants or antiplatelet drugs, herbs or supplements
  
• Anticonvulsants
  
• Blood pressure medications
  
• Central nervous system (CNS) depressants
  
• Diabetes medications
  
• Hormonal birth control
  
• Chrome P450 1A2 (CYP1A2) and cytochrome P450 2C19 (CPY2C19) substrates
  
• Fluvoxamine
  
• Immunosuppressants
  
• Seizure threshold lowering drugs
  

Talk with your doctor before starting any new medication or supplement, including melatonin. Together you can determine if the supplement is the right tool to address your sleep concerns, and if so, how you should be taking it. Here are a few things to keep in mind when you supplement with melatonin:

• ‌Start with a lose dose.‌ "There is no standardized doze for melatonin, yet most patients start at one mg [milligram] and may require up to five mg," Dr. Yaeger says. Consider starting with a supplement that has less than one milligram to start, per ConsumerLab. Taking high amounts (between five and 10 milligrams) is likely to leave you feeling sleepy and off-kilter the next day, according to ConsumerLab.
• ‌Time it properly.‌ It's best to take melatonin about two hours before you plan to go to bed — using it earlier might leave you drowsy during the day.
• ‌Watch for improvement.‌ You should notice a difference in your sleep within a week or two, according to Johns Hopkins Medicine. If it's not helping by then, you should stop taking it. Let your doctor know, too, so you can decide on what to try next to help you sleep.
• ‌Remember, it's a temporary fix.‌ Stop taking melatonin within four to eight weeks, since again, the side effects of long-term use aren't fully understood. If your sleep seems to be back on track, the melatonin did it's job. But if you're still having trouble sleeping, let your doctor know. You may have a chronic sleep problem that needs to be addressed.

If you'd rather not take melatonin, here are some other natural options that can help you get over a short-term sleep problem:

• ‌Exercise:‌ Regular physical activity — either in the morning or afternoon (but not right before bed) — is tied to better sleep and less daytime tiredness, according to the American Academy of Sleep Medicine (AASM).
  
• ‌Chamomile tea:‌ The herbal tea is rich in flavonoids that my support the brain's transition from being awake to going to sleep, per Johns Hopkins Medicine. Plus, warm liquids can be soothing before bed.
  
• ‌Tart cherry juice:‌ Adults with insomnia who sipped two 8-ounce glasses a day experienced an improvement in sleep within two weeks, found a March 2018 study published in the ‌American Journal of Therapeutics‌.
  
• ‌Valerian root:‌ Supplementing with the herb may help some people sleep better, but it can also cause headaches and weakness, per the Mayo Clinic.
  
• ‌Cognitive behavior therapy for insomnia (CBT-I):‌ CBT-I can teach you how to replace unhelpful thoughts and behaviors around sleep with healthier ones. It's worth considering if lifestyle changes or natural remedies haven't done enough. "It's the best way to treat chronic insomnia and should be considered as a first line of treatment," Dr. Kumar says.
  

Popping a melatonin supplement is fine for a few days or a few weeks, if you're dealing with jet lag or a short-term stressor that's affecting your sleep quality or leading to you sleeping fewer hours than usual. But you shouldn't take it for more than a month or two. The long-term effects haven't been well-studied, plus, it could get in the way of addressing a chronic underlying sleep problem.