Who Should Not Take 5-HTP

5-HTP is sold freely as a dietary supplement, so many people do not think about contraindications. But the substance directly increases the synthesis of serotonin, and in certain situations this can be dangerous — even life-threatening. The editorial team has compiled a list of groups of people for whom 5-HTP is contraindicated or permitted only at 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 use of drugs that raise the level or activity of serotonin. In such a combination the risk of serotonin syndrome grows — a state manifested by 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 present in some painkillers, anti-migraine and cough medicines and even an antibiotic. Many people do not know that the drug they are taking belongs to this class.

Especially dangerous are monoamine oxidase inhibitors: they block the breakdown of serotonin, and an additional precursor can quickly lead to its critical accumulation. After discontinuing an MAOI, its effect persists for about two more weeks.

It is also important to remember the “washout” period after discontinuing 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 is looking for “natural” help.

Depression, anxiety disorders.People with diagnosed depression should not take 5-HTP on their own instead of treatment: a 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 consulting a neurologist.

Pregnancy, lactation, children and the elderly

There are no safety studies 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 specialists’ supervision; they have nothing in common 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 the reach of children, like any medicine.

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, with age liver and kidney function changes. Intake in this group is possible only after a doctor or pharmacist reviews the list of medications.

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; usually the supplement is recommended to be stopped before surgery.

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

Carcinoid tumors.For patients with serotonin-producing tumors, an additional precursor is contraindicated: it can worsen 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 on intake is made by a doctor.

• Discontinue 5-HTP before elective surgery and inform the anesthesiologist.
• Warn your 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 purchase. If the answer to even one of the questions below is “yes,” taking 5-HTP on your own is unacceptable, and the decision must be made by a doctor.

Even if all the answers are negative, keep in mind that many drugs have a serotonergic effect that is not obvious — for example, cough remedies with dextromethorphan. Before starting, it is worth showing a pharmacist the list of everything you take, including herbal remedies.

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

Finally, it is worth answering honestly why you need 5-HTP. If the goal is to cope with low 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 because of 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, after warning your 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.
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