Who should not take 5-HTP

5-HTP is freely sold as a dietary supplement, so many people do not think about contraindications. But the substance directly increases serotonin synthesis, and in certain situations this can be dangerous — even life-threatening. The editors have compiled a list of groups of people for whom 5-HTP is contraindicated or permitted only by a doctor's decision, and explained the reason for each restriction.

Serotonergic drugs: the main contraindication

The most important contraindication to 5-HTP is the simultaneous intake of drugs that increase the level or activity of serotonin. In such a combination the risk of serotonin syndrome rises — a condition manifesting as agitation, tremor, muscle rigidity, fever and blood pressure instability, which can be fatal (Boyer, Shannon, 2005).

This group includes not only antidepressants. Serotonergic activity is possessed by some painkillers, anti-migraine and cough medications and even an antibiotic. Many people do not know that the drug they take belongs to this class.

Monoamine oxidase inhibitors are especially dangerous: they block the breakdown of serotonin, and an additional precursor can quickly lead to its critical accumulation. After stopping MAOIs, their effect persists for about another two weeks.

It is also important to remember the "washout" period after stopping antidepressants: for example, fluoxetine has a very long half-life, so the risk of interaction persists for weeks after the last tablet. Only a doctor can determine a safe interval.

Mental disorders and neurological diseases

Bipolar disorder.Serotonergic agents can provoke a switch into mania or hypomania in people with bipolar disorder. Therefore 5-HTP is contraindicated in this group, even if the person is currently in a depressive phase and seeking "natural" help.

Depression, anxiety disorders.People with diagnosed depression should not take 5-HTP on their own instead of treatment: the Cochrane review found the evidence base insufficient (Shaw et al., 2002). Moreover, most such patients receive antidepressants, with which 5-HTP is incompatible.

Parkinson's disease.5-HTP and levodopa are converted by the same enzyme — aromatic amino acid decarboxylase. In addition, levodopa preparations contain carbidopa, and the combination of 5-HTP with carbidopa has been described in the literature in connection with the development of a scleroderma-like disease (Sternberg et al., 1980). Many patients also take selegiline or rasagiline — MAO-B inhibitors.

Epilepsy and other neurological conditions.There is little direct evidence of harm, but the effect of serotonin on neuronal excitability and possible interactions with anticonvulsant drugs are sufficient grounds for a consultation with a neurologist.

Pregnancy, lactation, children and the elderly

There are no studies of the safety of 5-HTP during pregnancy and breastfeeding. Serotonin plays an important role in the development of the fetal nervous system, and interfering with its synthesis without medical indications is an unjustified risk. Therefore the supplement is contraindicated for pregnant and breastfeeding women.

5-HTP is also not recommended for children and adolescents. There are only isolated medical uses in pediatrics for rare disorders of neurotransmitter metabolism, carried out under the supervision of specialists; they have nothing to do with using the supplement for "calm" or "sleep."

Chewable forms of 5-HTP with a pleasant taste require special attention: they must be stored out of reach of children, like any medication.

In the elderly the risk of interactions is higher, because they more often take several drugs at once, among which there may be antidepressants, painkillers or migraine remedies. In addition, liver and kidney function changes with age. Intake in this group is possible only after a doctor or pharmacist reviews the list of drugs.

Surgery, tests and chronic diseases

Elective surgery.During surgical interventions and in the postoperative period, opioids (fentanyl, tramadol, pethidine) and other drugs with serotonergic activity are used. The anesthesiologist must be informed in advance about taking 5-HTP; the supplement is usually recommended to be stopped before surgery.

The 5-HIAA test.5-HTP is metabolized into 5-hydroxyindoleacetic acid, the level of which in urine is measured to diagnose neuroendocrine (carcinoid) tumors. Taking the supplement can distort the result, so it must be discontinued before the test as directed by a doctor.

Carcinoid tumors.For patients with tumors that produce serotonin, an additional precursor is contraindicated: it can intensify the symptoms of carcinoid syndrome.

Diseases of the GI tract, heart, liver and kidneys.People with irritable bowel syndrome, inflammatory bowel diseases, cardiac arrhythmias or impaired liver and kidney function may tolerate 5-HTP worse. For them the decision about intake is made by a doctor.

• Discontinue 5-HTP before elective surgery and inform the anesthesiologist.
• Warn the doctor before a urine test for 5-HIAA.
• With carcinoid tumors the supplement is contraindicated.

How to check yourself before taking it

The simplest way to avoid dangerous situations is to do a short self-check before buying. If the answer to even one of the questions below is "yes," independent use of 5-HTP is unacceptable, and the decision must be made by a doctor.

Even if all answers are negative, keep in mind that many drugs have serotonergic action non-obviously — for example, cough remedies with dextromethorphan. Before starting intake it is worth showing a pharmacist the list of everything you take, including herbal remedies.

If agitation, tremor, fever, strong palpitations or muscle pain or rash appear during intake, the supplement should be stopped immediately and medical attention sought.

Finally, it is worth honestly answering yourself why you need 5-HTP. If the goal is to cope with depressed mood, anxiety or insomnia, it is better to start with a doctor: these conditions have effective treatment.

Editorial conclusions

The main contraindication to 5-HTP is taking antidepressants, tramadol, triptans, MAO inhibitors and other serotonergic agents due to the risk of serotonin syndrome.

The supplement is also contraindicated in bipolar disorder, carcinoid tumors, during pregnancy and lactation, and for children; in Parkinson’s disease, epilepsy, liver and kidney diseases and before surgery the decision is made by a doctor.

Before a 5-HIAA test, intake must be stopped, warning the doctor.

Related editorial materials: "Side effects of 5-HTP," "5-HTP: what it is and how it works" and "Who should not take L-tyrosine."

References

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3. Shaw K, Turner J, Del Mar C. Tryptophan and 5-hydroxytryptophan for depression. Cochrane Database Syst Rev. 2002;(1):CD003198.
4. Sternberg EM, Van Woert MH, Young SN, et al. Development of a scleroderma-like illness during therapy with L-5-hydroxytryptophan and carbidopa. N Engl J Med. 1980;303(14):782–787.
5. Das YT, Bagchi M, Bagchi D, Preuss HG. Safety of 5-hydroxy-L-tryptophan. Toxicol Lett. 2004;150(1):111–122.
6. Birdsall TC. 5-Hydroxytryptophan: a clinically-effective serotonin precursor. Altern Med Rev. 1998;3(4):271–280.