Dec 292011

We’ve all heard about the side effects of certain prescription sleep aids.  But are there any melatonin side effects that we should worry about?  Are any of the side effects of melatonin severe?

Melatonin is a natural hormone produced by the pineal gland in the brain.  Under normal circumstance,  there is enough melatonin produced at nighttime to naturally help you get to sleep.  But this isn’t always the case,  our Circadian rhythms,  and natural sleep cycle can become out of balance.

Nobody is really sure what causes this.  But here are some possible causes:  Stress,  working odd hours,  bright light,  24 hour internet access and cable news,  poor diet,  and lack of exercise.  There are biological issues as well.  But how many of you check your email or use your smartphone right before bed?  Even short periods of light can disrupt melatonin production.

Melatonin Side Effects?

It might sound odd that a natural hormone found in all of our bodies could have side effects.  But all of these chemicals in our bodies interact with one another,  and can produce different effects.  Melatonin dosage also plays a big role in this.  The important thing is that we do our best to understand any possible melatonin side effects,  interactions or possible dangers.

Interactions and Cautions

  • Anti-depressant Medications-If you are taking anti-depressant medications,  consult your doctor first before taking melatonin.  In an animal study,  melatonin reduced the anti-depressant effects of Prozac.  It it not clear if the same effect would be observed in humans.  But this is a clear indication that you should consult with your doctor if taking any anti-depressants.  This is an issue because many people with depression might also be interested in taking melatonin for sleep,  but there are other options available.
  • Blood Thinning Medications-If you are taking any blood thinning medications such as warfarin (Coumadin),  you should consult your doctor before taking melatonin.  Melatonin may have an additive effect when added to these medications.  The reasons for this are unclear,  but if you combine these 2,  you should only do so under the supervision of a doctor;  and have your blood tested frequently.
  • Blood Pressure Medications-If you are taking blood pressure medications such as methoxamine (Vasoxyl),  you should consult your doctor and have your blood pressure tested frequently.  Melatonin may lower the effectiveness of such medications.
  • Immune Suppressing Drugs-Corticosteroids,  such as Prednisone, are given to suppress the immune system.  Melatonin may lower the effectiveness of such drugs.  Do not combine these 2 unless you do so under a doctor’s close supervision.  This applies to any drug used to suppress the immune system.
  • Depression-Some studies seem to indicate that melatonin may worsen symptoms of depression.  If you are depressed,  you should not take melatonin.  There are other natural insomnia supplements available such as L-tryptophan and valerian root.  These have also shown to be effective.  It should be noted however that there is a possibility for some valerian root side effects.
  • Driving and Operating Heavy Machinery-Melatonin may cause next day drowsiness.  Do not drive or operate heavy machinery until you know how melatonin will affect you.  Taking melatonin during the day will also cause drowsiness.
  • Other Insomnia Medications and Supplements-Melatonin will have an additive effect when mixed with over the counter and prescription sleep aids.  This also applies to natural sleep aids such as valerian root and L-tryptophan.  Combining these has not been well studied,  and any melatonin side effects could be multiplied.

Melatonin Side Effects

  • Vivid Dreams
  • Dizziness
  • Confusion
  • Anxiety
  • Mild Depression
  • Abdominal Discomfort
  • Day Time Drowsiness


Melatonin has bee shown to be effective for treating mild insomnia.  It is a hormone naturally found in the body,  so any melatonin side effects are rare and usually mild.  If you have any medical conditions,  or take any medications,  you should consult your doctor.  This way,  you can avoid any of the side effects of melatonin.

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