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5-HTP for Weight Control

5-HTP for Weight Control

Why Use

5-HTP

Why Do Dieters Use It?*

Some dieters say that 5-HTP helps suppress appetite and promote weight loss.

What Do the Advocates Say?*

Known for its ability to promote weight loss, 5-HTP has been shown to reduce appetite. It appears to do this by stimulating serotonin production in the brain. While 5-HTP has not yet been extensively researched, some human and double-blind studies have shown that 5-HTP promotes weight loss.

*Dieters and weight-management advocates may claim benefits for this supplement based on their personal or professional experience. These are individual opinions and testimonials that may or may not be supported by controlled clinical studies or published scientific articles.

Dosage & Side Effects

5-HTP

How Much Is Usually Taken by Dieters?

Appetite reduction and weight loss (averaging 11 pounds in 12 weeks) has occurred with amounts of 600 to 900 mg daily. In another clinical trial, 750 mg per day has been shown to be effective at decreasing carbohydrate and fat intake and promoting weight loss.

Side Effects

During the clinical trials described above, some people taking large amounts of 5-HTP experienced gastrointestinal upset (e.g. nausea) or, less often, headache, sleepiness, muscle pain, or anxiety .

A substance known as “Peak X” has been found in low concentrations in several over-the-counter 5-HTP preparations. Some researchers think this substance may be linked1 , 2 , 3 to toxicity previously reported4 , 5 , 6 in a 1989 L-tryptophan contamination incident. However, there is serious question about whether Peak X is actually the toxic agent and it may be unrelated to the problems previously associated with L-tryptophan.7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 Although two articles reported possible associations between 5-HTP consumption and toxicity symptoms similar to those attributed to contaminated L-tryprophan,15 , 16 evidence linking 5-HTP or Peak X with any toxicity symptoms remains speculative. Although the structure of Peak X has recently been identified, there is no firm evidence that this substance has caused or contributed to any toxicity or disease.17

Very high intakes of 5-HTP have caused muscle jerks in guinea pigs18 and both muscle jerks19 and diarrhea in mice.20 Injected 5-HTP has also caused kidney damage in rats.21 To date, these problems have not been reported in humans. “Serotonin syndrome,” a serious but uncommon condition caused by excessive amounts of serotonin, has not been reported to result from supplementation with 5-HTP; in theory it could be triggered by the supplement.22 However, the level of intake at which this toxic effect might potentially occur remains unknown.

Interactions with Supplements, Foods, & Other Compounds

5-HTP should not be taken with antidepressants, weight-control drugs, other serotonin-modifying agents, or substances known to cause liver damage, because in these cases 5-HTP may have excessive effects. People with liver disease may not be able to regulate 5-HTP adequately and those suffering from autoimmune diseases such as scleroderma may be more sensitive than others, to 5-HTP.23 These people should not take 5-HTP without consulting a knowledgeable healthcare professional. The safety of taking 5-HTP during pregnancy and breast-feeding is not known at this time.

Interactions with Medicines

Certain medicines interact with this supplement.

Types of interactions: Beneficial Adverse Check

Replenish Depleted Nutrients

  • none

Reduce Side Effects

  • none

Support Medicine

  • Selegiline

    Both L-tryptophan and 5-HTP have been used to treat depression . One controlled study showed that taking selegiline at the same time as 5-HTP enhanced the antidepressant effect when compared with 5-HTP alone.24 Further research is needed to determine whether taking selegiline and 5-HTP together might result in unwanted side effects.

Reduces Effectiveness

  • none

Potential Negative Interaction

  • Citalopram

    Citalopram increases serotonin activity in the brain. 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking either of these compounds with citalopram may increase citalopram-induced side effects. Dietary supplements of L-tryptophan (available only by prescription from special compounding pharmacists) taken with paroxetine (a drug that has similar actions as citalopram) caused headache, sweating, dizziness, agitation, restlessness, nausea, vomiting, and other symptoms.25

    Some doctors have used small amounts of L-tryptophan in combination with SSRIs, to increase their effectiveness. However, because of the potential for side effects, 5-HTP and L-tryptophan should never be taken in combination with citalopram or other SSRIs, unless a doctor is closely monitoring the combination. Foods rich in L-tryptophan do not appear to interact with citalopram or other SSRIs.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
  • Escitalopram

    Escitalopram increases serotonin activity in the brain. 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking either of these compounds with escitalopram may increase escitalopram-induced side effects. Dietary supplements of L-tryptophan (available only by prescription from special compounding pharmacists) taken with paroxetine (a drug that has similar actions as escitalopram) caused headache, sweating, dizziness, agitation, restlessness, nausea, vomiting, and other symptoms.26

    Some doctors have used small amounts of L-tryptophan in combination with SSRIs, to increase their effectiveness. However, because of the potential for side effects, 5-HTP and L-tryptophan should never be taken in combination with escitalopram or other SSRIs, unless a doctor is closely monitoring the combination. Foods rich in L-tryptophan do not appear to interact with escitalopram or other SSRIs.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
  • Fluoxetine

    Fluoxetine works by increasing serotonin activity in the brain. 5-HTP is converted to serotonin in the brain, and taking it with fluoxetine may increase fluoxetine-induced side effects. Until more is known, 5-HTP should not be taken with any SSRI drug, including fluoxetine.

  • Fluvoxamine

    Fluvoxamine works by increasing serotonin activity in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them with fluvoxamine may increase fluvoxamine-induced side effects. Until more is known, 5-HTP and L-tryptophan should not be taken with any SSRI drug, including fluvoxamine.

  • Paroxetine

    Paroxetine increases serotonin activity in the brain. 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking either of these compounds with paroxetine may increase paroxetine-induced side effects. Dietary supplements of L-tryptophan (available only by prescriptions from special compounding pharmacists) taken with paroxetine caused headache, sweating, dizziness, agitation, restlessness, nausea, vomiting, and other symptoms.27 Some doctors have used small amounts of L-tryptophan in combination with SSRIs, to increase the effectiveness of the latter. However, because of the potential for side effects, 5-HTP and L-tryptophan should never be taken in combination with paroxetine or other SSRIs, unless the combination is being closely monitored by a doctor. Foods rich in L-tryptophan do not appear to interact with paroxtine or other SSRIs.

    On the other hand, the combination of 45 mg DL-tryptophan (a synthetic variation of L-tryptophan) per pound of body weight (a relatively high dose) with zimelidine, a drug with a similar action to paroxetine, did not cause these side effects in another trial.28

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
  • Sertraline

    Sertraline increases serotonin activity in the brain. 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking either of these compounds with sertraline may increase sertraline-induced side effects.

    In one report, dietary supplements of L-tryptophan (available only by prescriptions from special compounding pharmacists) taken with paroxetine (a drug similar to sertraline) caused headache, sweating, dizziness, agitation, restlessness, nausea, vomiting, and other symptoms.29 On the other hand, the combination of 45 mg DL-tryptophan (a synthetic variation of L-tryptophan) per pound of body weight (a relatively high dose) with zimelidine, a drug with a similar action to sertraline, did not cause these side effects in another trial.30 Some doctors have used small amounts of L-tryptophan in combination with SSRIs, to increase the effectiveness of the latter. However, because of the potential for side effects, 5-HTP and L-tryptophan should never be taken in combination with sertraline or other SSRIs, unless the combination is being closely monitored by a doctor. Foods rich in L-tryptophan do not appear to interact with sertraline or other SSRIs.

  • Sibutramine

    The amino acids L-tryptophan and 5-hydroxytryptophan (5-HTP) are occasionally used to treat mental depression . Taking sibutramine with L-tryptophan or 5-HTP might result in a rare, but serious group of symptoms known as “serotonin syndrome.”31 Symptoms associated with serotonin syndrome may include confusion, anxiety, muscle weakness, incoordination, and vomiting. Therefore, individuals taking sibutramine should avoid supplementing with L-tryptophan and 5-HTP.

  • Tramadol

    Tramadol, which blocks serotonin reuptake in the brain, has been associated with two cases of serotonin syndrome.32 , 33 5-HTP and L-tryptophan are converted to serotonin in the brain. While no interactions have yet been reported with tramadol and 5-HTP or L-tryptophan, taking 5-HTP or L-tryptophan with tramadol may increase the risk of tramadol-induced side effects, including serotonin syndrome.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
  • Venlafaxine

    Venlafaxine, a potent serotonin reuptake inhibitor, has been associated with several cases of serotonin syndrome.34 , 35 , 36 , 37 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking them with venlafaxine may increase venlafaxine-induced side effects. While no interactions with venlafaxine and 5-HTP or L-tryptophan have been reported, until more is known, people taking venlafaxine are cautioned to avoid 5-HTP or L-tryptophan.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
  • Zolpidem

    Nine cases of zolpidem-induced hallucinations associated with serotonin reuptake inhibiting antidepressants have been reported, some lasting for several hours.38 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking them with zolpidem may increase zolpidem-induced hallucinations, though no interactions have yet been reported with zolpidem and 5-HTP or L-tryptophan.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Explanation Required

  • Almotriptan

    Triptans work by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them with eletriptan could increase eletriptan-induced side effects. However, no interactions have yet been reported with eletriptan and 5-HTP or L-tryptophan.

  • Carbidopa

    5-HTP and carbidopa have been reported to improve intention myoclonus (a neuromuscular disorder) in some human cases but not others.39 , 40 , 41 Several cases of scleroderma-like illness have been reported in patients using carbidopa and 5-HTP for intention myoclonus.42 , 43 , 44

  • Carbidopa-Levodopa

    Several cases of scleroderma-like illness have been reported in patients using carbidopa and 5-HTP (5-Hydroxytryptophan).45 , 46 , 47 People taking carbidopa should not supplement 5-HTP without consulting the prescribing physician.

  • Eletriptan

    Eletriptan works by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them with eletriptan could increase eletriptan-induced side effects. However, no interactions have yet been reported with eletriptan and 5-HTP or L-tryptophan.

  • Frovatriptan

    Triptans work by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them at the same time as 5-HT1 agonists could increase unwanted side effects. However, at the time of this writing there are no known interactions with 5-HT1 agonists and 5-HTP or L-tryptophan.48

  • Naratriptan

    Triptans work by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them at the same time as 5-HT1 agonists could increase unwanted side effects. However, at the time of this writing there are no known interactions with 5-HT1 agonists and 5-HTP or L-tryptophan.49

  • Rizatriptan

    Triptans work by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them at the same time as 5-HT1 agonists could increase unwanted side effects. However, at the time of this writing there are no known interactions with 5-HT1 agonists and 5-HTP or L-tryptophan.50

  • Sumatriptan

    Sumatriptan works by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them with sumatriptan could increase sumatriptan-induced side effects. However, no interactions have yet been reported with sumatriptan and 5-HTP or L-tryptophan.

  • Zolmitriptan

    Zolmitriptan works by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them with zolmitriptan could increase zolmitriptan-induced side effects. However, no interactions have yet been reported with zolmitriptan and 5-HTP or L-tryptophan.

More Resources

5-HTP

Where to Find It

5-HTP is not present in significant amounts in a typical diet. The human body manufactures 5-HTP from L-tryptophan, a natural amino acid found in most dietary proteins. However, eating food that contains L-tryptophan does not significantly increase 5-HTP levels. Supplemental 5-HTP is naturally derived from the seeds of Griffonia simplicifolia, a West African medicinal plant.

Resources

See a list of books, periodicals, and other resources for this and related topics.

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