The Vampire Hormone: What Dental Hygienists Need to Know

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Don’t think this is another informative essay telling us women that our hormones will suck the life out of us. I’m speaking of melatonin. Melatonin has the nickname of vampire hormone because its production begins when it starts getting dark and shies away from the light.

Anyone who knows me observes that anything related to sleep always makes me all giddy inside.  I will talk forever about shut-eye, catching some z’s, or hitting the hay.

The Rise of Melatonin

Melatonin is something most of us have heard about, but many of us may not fully understand what it is. Melatonin is a hormone released from the pineal gland soon after dusk and sets the internal clock by synchronizing the day-night-rhythm in both people and animals. Some have described it as a bullhorn that shouts a message to the brain that, because it’s dark, it’s time to start shutting down.

When I took pharmacology back in hygiene school during the Stone Age, melatonin wasn’t even mentioned in my class. Frankly, melatonin wasn’t identified until the 1950s. These days you see it everywhere in a synthetic form, and it’s discussed as a gamechanger for sleep.

Looking at health histories and talking to friends, one would think that most people’s natural bullhorns are plugged up, and the world needs these supplements to be able to fall asleep. As we age, melatonin decreases, adding to the list of the joys of aging. So, popular culture would have me believe that between urinary incontinence and collagen depletion, I will be sitting on the toilet in the middle of the night, wide awake with my skin hanging at my ankles. Excuse me, I digressed.

The Dawning of Serotonin Levels

Melatonin is synthesized from the essential amino acid tryptophan, the same tryptophan that puts us in a turkey coma on Thanksgiving. This is the part where the science nerds perk up. Essential amino acids cannot be made by the body and must come from food. The highest tryptophan foods are red meat, fish, poultry, milk, and eggs. But for our vegetarian and vegan friends, there are many plant-based options available too, such as chickpeas, cauliflower, quinoa, and cashews.

Serotonin is a brain neurotransmitter that is necessary as a messenger and regulator for our melatonin. To metabolize tryptophan into serotonin, you need nutrients such as vitamin B6, niacin, and glutathione. In short, here is how it works: Tryptophan is an essential amino acid that is the precursor for the formation of serotonin and melatonin. The pineal gland is the convertor of tryptophan to serotonin to melatonin.

Serotonin levels are highest during daylight hours then drop at darkness as the pineal gland converts most of the serotonin into melatonin. Anytime you want to increase your serotonin, take a walk in the sunshine. Eating more vegetables such as tomato, pumpkin, and spinach can increase natural melatonin levels as well as certain fruits, often the tropical ones. Pineapple can increase melatonin 266%, bananas 180%, and oranges by 47%.1

“Calcium can help the brain use the amino acid tryptophan to manufacture the sleep-inducing substance melatonin. This explains why dairy products, which contain both tryptophan and calcium, are of the top sleep-inducing foods.” (Williams Sears, MD)

Something to know about melatonin is that it regulates the timing of sleep but does not participate in sleep itself. It helps your body know when it is time to sleep and when to wake up and is regulated by light. Bright lights in the evening suppress the normal rise in melatonin, pushing our sleep onset time later. Thomas Edison, were you a friend or foe?

As the night progresses, melatonin decreases, which gets us ready to wake. Light begins to enter the brain, whether directly or through your eyelids, and the pineal gland shuts off the release of the hormone. The peak of melatonin is from about 11 pm through 3 am.

You can imagine that as we lengthen our days, staying up later and later with bright lights, we are changing the natural pineal gland rhythm. People who have a disrupted sleep schedule or are traveling across time zones are at a greater risk of having their melatonin levels out of whack.

Melatonin Supplements

Supplemental melatonin is not as powerful a sleep aid as many imagine. But what often happens is that taking melatonin in pill form shows a placebo effect. This isn’t surprising. After all, placebos have the most reliable effect in all of pharmacology. If you think it works, it works.

A meta-analysis done in 2005 looked at 17 trials analyzing the benefits in different aspects of sleep. Overall, it helped sleep onset by four minutes, efficiency by 2.2%, and duration by 12.8 minutes.2 Is that remarkable? Unfortunately, no.

Many people are taking this supplement, which may not be effective or can even be contraindicated. Overuse is common when we so often believe more is better. Physicians recommend 0.5mg to 2 mg about 30 minutes before bed. A dose of 0.1-0.3 before going to bed is adequate and, at this level, will raise the nocturnal plasma concentration of melatonin into the normal range.3

 We see pharmacies and discount stores selling the supplements with doses of 5 mg and 10 mg everywhere. A dose of 10 mg can actually raise plasma concentrations 60 times their normal value.4 There are many schools of thought on proper dosage, but no matter what, it should be discussed with a physician. Several over-the-counter drugs are not regulated by the FDA, melatonin supplements included. They are made in a lab with synthetic ingredients or with cow urine (delish), and the range in a pill can be from 83% less than what the label says to 478% more.5

Melatonin is similar to most drugs in that by being exposed to too much, the body may become unresponsive, and the drug stops doing what it is supposed to do.

Additional Uses and Concerns

Many positive effects of melatonin are currently being studied, including that:

  • High doses of melatonin with chemotherapy might reduce tumor size
  • Taking melatonin at bedtime for four weeks may reduce temporomandibular disorder (or TMD) pain
  • Taking melatonin can improve low blood platelet counts associated with cancer and other disorders
  • Taking melatonin daily for eight weeks for patients with endometriosis may reduce pain, and studies have shown the neuroprotective benefits in developing fetuses in pregnant women as well as perhaps reducing the risk of pre-eclampsia6

Taking melatonin for any of these conditions, but especially while pregnant must be discussed with a physician – period. Melatonin has been designated in the N class by the FDA, which means is it has not been assigned a classification of the drug’s potential for birth defects and is not able to put into a specified category.

Some studies have suggested it may be associated with an increase in developmental disorders in the baby as well as abnormalities in ovarian function. Melatonin plays an important role in our immune system and inflammatory control.7,8 It is important to note the beneficial roles of melatonin as a naturally occurring hormone may not imply the same benefits when supplemented.

Drug interactions with melatonin are numerous, and there are many that we should review for our health as well as our patients, such as:

  • Verapamil, a calcium channel blocker
  • Any drugs that lower seizure thresholds, such as ADHD medications and methamphetamines
  • Additionally, narcotics, immunosuppressants, antihistamines, antidepressants, antibiotics, antiarrhythmics, and anesthetics.

Nifedipine, a drug commonly used for hypertension and nearly all blood pressure medications when used with melatonin, has been shown to make blood pressure worse. Even common drugs as contraceptives, CNS depressants, sedatives, sleep aids, and caffeine can cause negative interactions with melatonin.

Caffeine is one that I find interesting because it may decrease the body’s production of natural melatonin. But when combined with melatonin supplements, caffeine may have the opposite effect, thus increasing serum levels and adding to the effects of the supplement. Melatonin can spike blood sugar, so before using it, diabetics or people with pre-diabetes should discuss it with their physician.

I have myself have taken melatonin without knowing its many intricacies. Make no mistake, it should still be treated as a drug similar to caffeine and alcohol, which we don’t put the “drug” label on. I am not trying to dissuade you from taking the supplement. I am all about getting proper sleep. While melatonin may help some, there is sometimes no quick fix or easy answer on getting 40 winks, and considering other alternatives may be more beneficial.

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  1. Johns, N.P., Johns, J., Porasuphatana, S., Plaimee, P., Sae-Teaw, M. Dietary Intake of Melatonin from Tropical Fruit Altered Urinary Excretion of 6-Sulfatoxymelatonin in Healthy Volunteers. Journal of Agricultural and Food Chemistry.2013; 61(4): 913-919. DOI: 10.1021/jf300359a. Retrieved from
  2. Brzezinski, A., Vangel, M.G., Wurtman, R.J., Norrie, G., Zhdanova, I., Ben-Shushan, A., Ford, I. Effects of exogenous melatonin on sleep: a meta-analysis. Sleep Med Rev.2005 Feb; 9(1): 41–50. DOI: 10.1016/j.smrv.2004.06.004. Retrieved from
  3. Vural, E.M.S., van Munster, B.C., de Rooij, S.E. Optimal Dosages for Melatonin Supplementation Therapy in Older Adults: A Systematic Review of Current Literature. Drugs Aging. 2014; 31441–451. DOI:10.1007/s40266-014-0178-0. Retrieved from
  4. Dollins, A.B., Zhdanova, I.V., Wurtman, R.J., Lynch, H.J., Deng, M.H. Effect of inducing nocturnal serum melatonin concentrations in daytime on sleep, mood, body temperature, and performance. Proceedings of the National Academy of Sciences. Mar 1994; 91(5): 1824-1828; DOI:10.1073/pnas.91.5.1824. Retrieved from
  5. Erland, L.A., Saxena, P.K. Melatonin Natural Health Products and Supplements: Presence of Serotonin and Significant Variability of Melatonin Content. J Clin Sleep Med. 2017; 13(2): 275–281. DOI:10.5664/jcsm.6462. Retrieved from
  6. Hobson, S.R., Gurusinghe, S., Lim, R., Alers, N.O., Miller, S.L., Kingdom, J.C., Wallace, E.M. Melatonin improves endothelial function in vitro and prolongs pregnancy in women with early-onset preeclampsia. J Pineal Res.2018 May 16: e12508. DOI: 10.1111/jpi.12508. Retrieved from
  7. Lin, G.J., Huang, S.H., Chen, S.J., Wang, C.H., Chang, D.M., Sytwu, H.K. Modulation by melatonin of the pathogenesis of inflammatory autoimmune diseases. Int J Mol Sci. 2013; 14(6): 11742–11766. DOI:10.3390/ijms140611742. Retrieved from
  8. Szczepanik, M. Melatonin and its influence on immune system. Journal of Physiology and Pharmacology: an official journal of the Polish Physiological Society. 2008; 8(Suppl 6): 115-24.  Retrieved from
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Anne O. Rice, RDH, BS
Anne O. Rice, RDH, BS, has been a clinical dental hygienist for over 30 years and received her degree from Wichita State University. Her oral-systemic passion led her to found Oral Systemic Seminars in 2017, in which she now devotes her time, focus, and study primarily to dementia prevention and sleep hygiene. She completed the Bale Doneen Preceptorship for Cardiovascular Disease Prevention for Healthcare Practitioners. In 2020 Anne became certified as a Longevity Specialist with the Alzheimer’s Research and Dementia Foundation, a Fellow with The American Academy of Oral Systemic Health, and in 2021 published her manuscript Alzheimer’s Disease and Oral-Systemic Health: Bidirectional Care Integration Improving Outcomes. The perspective article was part of a research topic: Integrating Oral and Systemic Health: Innovations in Transdisciplinary Science, Health Care and Policy. Anne is a consultant with Weill Cornell Medical Center’s Alzheimer’s Prevention Clinic and is a consultant with Florida Atlantic College of Medicine under the direction of Dr. Richard Isaacson.