This is an unofficial archive of PsychonautWiki as of 2025-08-11T15:14:44Z. Content on this page may be outdated, incomplete, or inaccurate. Please refer to the original page for the most up-to-date information.
'''5-Hydroxytryptophan''' (also known as '''5-HTP''', and '''Oxitriptan''') is a naturally occurring amino acid. It acts as a chemical precursor as well as a metabolic intermediate in the biosynthesis of the [[neurotransmitters]] [[serotonin]] and [[melatonin]] from [[tryptophan]] in the human body.{{citation needed}} It is available over the counter in the United States, United Kingdom, and Canada as a dietary supplement and is sometimes used as an [[antidepressant]], sleep aid, and appetite suppressant. In some European countries, it is marketed as a prescription drug for the treatment of major depression.<ref>https://books.google.com/books?id=5GpcTQD_L2oC&lpg=PA1528&pg=PA773&hl=en#v=onepage&q&f=false | Swiss Pharmaceutical Society (2000). Index Nominum 2000: International Drug Directory (Book with CD-ROM). Boca Raton: Medpharm Scientific Publishers. ISBN 3-88763-075-0.</ref>
'''5-Hydroxytryptophan''' (also known as '''5-HTP''' and '''oxitriptan''') is a naturally occurring chemical substance and a metabolic intermediate in the biosynthesis of [[serotonin]] in the human body.{{citation needed}}
5-HTP is also popularly consumed by users of [[MDMA]] and other serotonin-releasing agents to try to reduce the negative [[MDMA#After_effects|after effects]] that begin during the substance's [[duration|come down]] period, including [[anxiety]], [[depression]], and [[cognitive fatigue]].<ref>http://www.sciencedirect.com/science/article/pii/S0306452207006732 | Wang, X.; Baumann, M. H.; Dersch, C. M.; Rothman, R. B. (2007-08-10). "Restoration of 3,4-methylenedioxymethamphetamine-induced 5-HT depletion by the administration of l-5-hydroxytryptophan". Neuroscience. 148 (1): 212–220. doi:10.1016/j.neuroscience.2007.05.024. PMID 17629409.</ref> Since 5-HTP is a precursor for the neurotransmitter [[serotonin]] and MDMA administration both depletes serotonin levels in the brain as well as inhibit the enzyme needed to produce it (i.e. tryptophan hydroxylase) for a short period after,<ref>Acute inactivation of tryptophan hydroxylase by amphetamine analogs involves the oxidation of sulfhydryl sites | http://www.maps.org/images/pdf/1989_stone_1.pdf</ref> it is believed that taking 5-HTP in the days after coming down will speed up the production of serotonin and decrease the time needed to recover (though there are many popular misconceptions and controversies as to just how effective it is for this purpose).{{Citation needed}}
5-HTP is available over the counter in the United States, United Kingdom, and Canada as a dietary supplement and is sometimes used as an [[antidepressant]], sleep aid, and appetite suppressant. It is marketed in some European countries as a prescription drug for the treatment of major depression.<ref>{{cite book | vauthors=((Society, S. P.)) | date= 2000 | title=Index Nominum 2000: International Drug Directory | publisher=Taylor & Francis | isbn=9783887630751}}</ref>
5-HTP should not be taken until 12 hours after one's last dose of MDMA because combining the two substances could synergistically increase brain's serotonin levels to dangerous levels -- resulting in a potentially life-threatening condition called [[serotonin syndrome]].
5-HTP is also popularly consumed by users of [[MDMA]] and other serotonin-releasing agents to try to reduce the negative [[MDMA#After_effects|after effects]] that begin during the substance's [[duration|come down]] period, including [[anxiety]], [[depression]], and [[cognitive fatigue]].<ref>h{{cite journal | vauthors=((Wang, X.)), ((Baumann, M. H.)), ((Dersch, C. M.)), ((Rothman, R. B.)) | journal=Neuroscience | title=Restoration of 3,4-methylenedioxymethamphetamine-induced 5-HT depletion by the administration of l-5-hydroxytryptophan | volume=148 | issue=1 | pages=212–220 | date=10 August 2007 | url=https://www.sciencedirect.com/science/article/pii/S0306452207006732 | issn=0306-4522 | doi=10.1016/j.neuroscience.2007.05.024}}</ref>
Since 5-HTP is a precursor for the neurotransmitter [[serotonin]] and MDMA administration both depletes serotonin levels in the brain as well as inhibit the enzyme needed to produce it (i.e. tryptophan hydroxylase) for a short period after,<ref>{{cite journal | vauthors=((Stone, D. M.)), ((Johnson, M.)), ((Hanson, G. R.)), ((Gibb, J. W.)) | journal=European Journal of Pharmacology: Molecular Pharmacology | title=Acute inactivation of tryptophan hydroxylase by amphetamine analogs involves the oxidation of sulfhydryl sites | volume=172 | issue=1 | pages=93–97 | date= March 1989 | url=https://linkinghub.elsevier.com/retrieve/pii/0922410689900485 | issn=09224106 | doi=10.1016/0922-4106(89)90048-5}}</ref> it is believed that taking 5-HTP in the days after coming down will speed up the production of serotonin and decrease the time needed to recover (though there are many popular misconceptions and controversies as to just how effective it is for this purpose).{{Citation needed}}
5-HTP should not be taken until 12 hours after one's last dose of MDMA because combining the two substances could interact to increase the brain's serotonin levels to dangerous levels, which can result in a potentially life-threatening condition called [[serotonin syndrome]].
==Chemistry==
==Chemistry==
5-HTP or 5-Hydroxytryptophan is a synthetic indole alkaloid molecule of the [[tryptamine]] class. Tryptamines share a core structure comprised of a bicyclic indole heterocycle attached at R<sub>3</sub> to an amino group via an ethyl side chain. 5-HTP is substituted at R<sub>5</sub> of its indole heterocycle with a hydroxy (OH) functional group. It also contains propanoic acid group bound to the terminal amine R<sub>N</sub> of its tryptamine backbone. 5-HTP is the 5-hydroxy analog of [[tryptophan]], and is sold in its levorotary isomer form. 5-HTP contains the core structure of [[serotonin]] with the addition of a propanoic acid at R<sub>N</sub>, and is converted by the body into serotonin by metabolic reactions.
5-HTP or 5-Hydroxytryptophan is a synthetic indole alkaloid molecule of the [[tryptamine]] class. Tryptamines share a core structure comprised of a bicyclic indole heterocycle attached at R<sub>3</sub> to an amino group via an ethyl side chain. 5-HTP is substituted at R<sub>5</sub> of its indole heterocycle with a hydroxy (OH) functional group. It also contains propanoic acid group bound to the terminal amine R<sub>N</sub> of its tryptamine backbone. 5-HTP is the 5-hydroxy analog of [[tryptophan]], and is sold in its levorotary isomer form. 5-HTP contains the core structure of [[serotonin]] with the addition of a propanoic acid at R<sub>N</sub>, and is converted by the body into serotonin by metabolic reactions.
==Pharmacology==
==Pharmacology==
The psychoactive action of 5-HTP is derived from its increase in production of [[serotonin]] in central nervous system tissue. 5-HTP is decarboxylated to serotonin (5-hydroxytryptamine or 5-HT) by the enzyme 'aromatic-L-amino-acid decarboxylase', with the help of vitamin B<sub>6</sub>.<ref>https://www.ncbi.nlm.nih.gov/pubmed/6983619 | Effect of pyridoxal phosphate deficiency on aromatic L-amino acid decarboxylase activity with L-DOPA and L-5-hydroxytryptophan as substrates in rats.</ref> This reaction occurs both in nervous tissue and in the liver.<ref>https://www.ncbi.nlm.nih.gov/pubmed/6974228 | Characteristics of dihydroxyphenylalanine/5-hydroxytryptophan decarboxylase activity in brain and liver of cat.</ref> 5-HTP crosses the blood–brain barrier, while 5-HT (serotonin) does not.<ref>https://www.ncbi.nlm.nih.gov/pubmed/18445233 | Augmented brain 5-HT crosses the blood-brain barrier through the 5-HT transporter in rat.</ref>
The psychoactive action of 5-HTP is derived from its increase in production of [[serotonin]] in central nervous system tissue. 5-HTP is decarboxylated to serotonin (5-hydroxytryptamine or 5-HT) by the enzyme 'aromatic-L-amino-acid decarboxylase', with the help of vitamin B<sub>6</sub>.<ref>{{cite journal | vauthors=((Rahman, M. K.)), ((Nagatsu, T.)), ((Sakurai, T.)), ((Hori, S.)), ((Abe, M.)), ((Matsuda, M.)) | journal=Japanese Journal of Pharmacology | title=Effect of pyridoxal phosphate deficiency on aromatic L-amino acid decarboxylase activity with L-DOPA and L-5-hydroxytryptophan as substrates in rats | volume=32 | issue=5 | pages=803–811 | date= October 1982 | issn=0021-5198 | doi=10.1254/jjp.32.803}}</ref> This reaction occurs both in nervous tissue and in the liver.<ref>{{cite journal | vauthors=((Bouchard, S.)), ((Bousquet, C.)), ((Roberge, A. G.)) | journal=Journal of Neurochemistry | title=Characteristics of dihydroxyphenylalanine/5-hydroxytryptophan decarboxylase activity in brain and liver of cat | volume=37 | issue=3 | pages=781–787 | date= September 1981 | issn=0022-3042 | doi=10.1111/j.1471-4159.1982.tb12555.x}}</ref> 5-HTP crosses the blood–brain barrier, while 5-HT (serotonin) does not.<ref>{{cite journal | vauthors=((Nakatani, Y.)), ((Sato-Suzuki, I.)), ((Tsujino, N.)), ((Nakasato, A.)), ((Seki, Y.)), ((Fumoto, M.)), ((Arita, H.)) | journal=The European Journal of Neuroscience | title=Augmented brain 5-HT crosses the blood-brain barrier through the 5-HT transporter in rat | volume=27 | issue=9 | pages=2466–2472 | date= May 2008 | issn=1460-9568 | doi=10.1111/j.1460-9568.2008.06201.x}}</ref>
Excess 5-HTP, especially when administered with vitamin B<sub>6</sub>, is thought to be metabolized and excreted.<ref>Biochemical properties and kinetic parameters of dihydroxyphenylalanine--5-hydroxytryptophan decarboxylase in brain, liver, and adrenals of cat | doi=10.1139/o79-126}}</ref><ref>https://www.ncbi.nlm.nih.gov/pubmed/1088369 | On the tryptophan-serotonin metabolism in manic-depressive disorders. Changes in plasma 5-HT and 5-HIAA levels and urinary 5-HIAA excretion following oral loading of L-5HTP in patients with depression</ref>
Excess 5-HTP, especially when administered with vitamin B<sub>6</sub>, is thought to be metabolized and excreted.<ref>{{cite journal | vauthors=((Bouchard, S.)), ((Roberge, A. G.)) | journal=Canadian Journal of Biochemistry | title=Biochemical properties and kinetic parameters of dihydroxyphenyialanine – 5-hydroxytryptophan decarboxylase in brain, liver, and adrenals of cat | volume=57 | issue=7 | pages=1014–1018 | date=1 July 1979 | url=http://www.nrcresearchpress.com/doi/10.1139/o79-126 | issn=0008-4018 | doi=10.1139/o79-126}}</ref><ref>{{cite journal | vauthors=((Amamoto, T.)), ((Sarai, K.)) | journal=Hiroshima Journal of Medical Sciences | title=On the tryptophan-serotonin metabolism in manic-depressive disorders. Changes in plasma 5-HT and 5-HIAA levels and urinary 5-HIAA excretion following oral loading of L-5HTP in patients with depression | volume=25 | issue=2–3 | pages=135–140 | date= September 1976 | issn=0018-2052}}</ref>
==Subjective effects==
==Subjective effects==
Line 21:
Line 24:
|{{effects/physical|
|{{effects/physical|
For some individuals, 5-HTP can cause the following side effects (although rare, and typically at higher dosages).
For some individuals, 5-HTP can cause the following side effects (although rare, and typically at higher dosages).
*'''[[Effect::Sedation]]'''
*'''[[Effect::Stimulation]]'''
*'''[[Effect::Bodily control enhancement]]'''
*'''[[Effect::Abnormal heartbeat]]'''
*'''[[Effect::Abnormal heartbeat]]'''
*'''[[Effect::Appetite suppression]]'''
*'''[[Effect::Appetite suppression]]'''
*'''[[Effect::Bodily control enhancement]]'''
*'''[[Effect::Diarrhea]]'''
*'''[[Effect::Diarrhea]]'''
*'''[[Effect::Dizziness]]
*'''[[Effect::Dizziness]]
Line 32:
Line 37:
*'''[[Effect::Increased heart rate]]'''
*'''[[Effect::Increased heart rate]]'''
*'''[[Effect::Nausea]] and vomiting'''
*'''[[Effect::Nausea]] and vomiting'''
*'''[[Effect::Sedation]]'''
*'''[[Effect::Stimulation]]'''
*'''[[Effect::Stomach bloating]]'''
*'''[[Effect::Stomach bloating]]'''
*'''[[Effect::Stomach cramps]]'''
*'''[[Effect::Stomach cramps]]'''
Line 44:
Line 47:
*'''[[Effect::Color enhancement]]'''
*'''[[Effect::Color enhancement]]'''
*'''[[Effect::Drifting]]'''
*'''[[Effect::Drifting]]'''
*'''[[Effect::Depth perception distortions]]'''
}}
}}
Line 66:
Line 70:
*'''[[Effect::Auditory hallucinations|Hallucinations]]''' - Auditory hallucinations have been reported on 5-HTP, however they are rare and only occur at high dosages.
*'''[[Effect::Auditory hallucinations|Hallucinations]]''' - Auditory hallucinations have been reported on 5-HTP, however they are rare and only occur at high dosages.
}}
}}
}}
}}
===Experience reports===
Anecdotal reports which describe the effects of this compound within our [[experience index]] include:
Due to the conversion of 5-HTP into serotonin by the liver, with prolonged use, there may be a significant risk of heart valve disease from serotonin's effect on the heart, which is thought to be due to agonism of the 5-HT<sub>2B</sub> receptors present on it.<ref>https://www.ncbi.nlm.nih.gov/pubmed/15781732 | Long-term serotonin administration induces heart valve disease in rats.</ref><ref>https://www.ncbi.nlm.nih.gov/pubmed/12466135 | Serotonin mechanisms in heart valve disease II: the 5-HT2 receptor and its signaling pathway in aortic valve interstitial cells.</ref> However, this may be avoided if Epigallocatechin gallate (more well known as 'EGCG') is taken before the 5-HTP. This is said to protect the heart, and therefore reduce the risks of any heart damage.<ref>https://www.ncbi.nlm.nih.gov/pubmed/27374189 | EGCG, a green tea catechin, attenuates the progression of heart failure induced by the heart/muscle-specific deletion of MnSOD in mice.</ref><ref>https://www.ncbi.nlm.nih.gov/pubmed/17906191 | Effects of green tea and EGCG on cardiovascular and metabolic health.</ref>
Due to the conversion of 5-HTP into serotonin by the liver, with prolonged use, there may be a significant risk of heart valve disease from serotonin's effect on the heart, which is thought to be due to agonism of the 5-HT<sub>2B</sub> receptors present on it.<ref>{{cite journal | vauthors=((Gustafsson, B. I.)), ((Tømmerås, K.)), ((Nordrum, I.)), ((Loennechen, J. P.)), ((Brunsvik, A.)), ((Solligård, E.)), ((Fossmark, R.)), ((Bakke, I.)), ((Syversen, U.)), ((Waldum, H.)) | journal=Circulation | title=Long-term serotonin administration induces heart valve disease in rats | volume=111 | issue=12 | pages=1517–1522 | date=29 March 2005 | issn=1524-4539 | doi=10.1161/01.CIR.0000159356.42064.48}}</ref><ref>{{cite journal | vauthors=((Xu, J.)), ((Jian, B.)), ((Chu, R.)), ((Lu, Z.)), ((Li, Q.)), ((Dunlop, J.)), ((Rosenzweig-Lipson, S.)), ((McGonigle, P.)), ((Levy, R. J.)), ((Liang, B.)) | journal=The American Journal of Pathology | title=Serotonin mechanisms in heart valve disease II: the 5-HT2 receptor and its signaling pathway in aortic valve interstitial cells | volume=161 | issue=6 | pages=2209–2218 | date= December 2002 | issn=0002-9440 | doi=10.1016/S0002-9440(10)64497-5}}</ref>
It has been suggested that 5-HTP may cause eosinophilia-myalgia syndrome (EMS), a serious condition which results in extreme muscle tenderness, myalgia, and blood abnormalities. However, there is evidence to show that EMS was likely caused by a contaminant in certain 5-HTP supplements instead of the substance itself.<ref>https://www.ncbi.nlm.nih.gov/pubmed/7699627 | An eosinophilia-myalgia syndrome related disorder associated with exposure to L-5-hydroxytryptophan.</ref>
It has been suggested that 5-HTP may cause eosinophilia-myalgia syndrome (EMS), a serious condition which results in extreme muscle tenderness, myalgia, and blood abnormalities. However, there is evidence to show that EMS was likely caused by a contaminant in certain 5-HTP supplements instead of the substance itself.<ref>{{cite journal | vauthors=((Michelson, D.)), ((Page, S. W.)), ((Casey, R.)), ((Trucksess, M. W.)), ((Love, L. A.)), ((Milstien, S.)), ((Wilson, C.)), ((Massaquoi, S. G.)), ((Crofford, L. J.)), ((Hallett, M.)) | journal=The Journal of Rheumatology | title=An eosinophilia-myalgia syndrome related disorder associated with exposure to L-5-hydroxytryptophan | volume=21 | issue=12 | pages=2261–2265 | date= December 1994 | issn=0315-162X}}</ref>
===Dangerous interactions===
===Dangerous interactions===
Although many substances are safe on their own, they can become dangerous and even life-threatening when combined with other substances. The list below contains some common potentially dangerous combinations, but may not include all of them. Certain combinations may be safe in low doses of each but still increase the potential risk of death. Independent research should always be done to ensure that a combination of two or more substances is safe before consumption.
Although many substances are safe on their own, they can become dangerous and even life-threatening when combined with other substances. The list below contains some common potentially dangerous combinations, but may not include all of them. Certain combinations may be safe in low doses of each, but still increase the potential risk of death. Independent research should always be done to ensure that a combination of two or more substances is safe before consumption.
Combinations in the list below may increase the amount of neurotransmitters, such as serotonin, to dangerous or even fatal levels, resulting in life-threatening [[serotonin syndrome]].
Combinations in the list below may increase the amount of neurotransmitters, such as serotonin, to dangerous or even fatal levels, resulting in life-threatening [[serotonin syndrome]].
*'''[[DangerousInteraction::Selective serotonin re-uptake inhibitors]] (SSRIs)''' - When combined with antidepressants of the SSRI class, high doses of 5-HTP can cause acute serotonin syndrome in rats.<ref name="one">https://www.ncbi.nlm.nih.gov/pubmed/18499101 | Characterization of serotonin-toxicity syndrome (toxidrome) elicited by 5-hydroxy-l-tryptophan in clorgyline-pretreated rats.</ref><ref name="two">https://www.ncbi.nlm.nih.gov/pubmed/16488409 | Effects of co-administration of a selective serotonin reuptake inhibitor and monoamine oxidase inhibitors on 5-HT-related behavior in rats.</ref>
*'''[[DangerousInteraction::SSRIs]]''' - When combined with antidepressants of the SSRI class, high doses of 5-HTP can cause acute serotonin syndrome in rats.<ref name="one">{{cite journal | vauthors=((Ma, Z.)), ((Zhang, G.)), ((Jenney, C.)), ((Krishnamoorthy, S.)), ((Tao, R.)) | journal=European Journal of Pharmacology | title=Characterization of serotonin-toxicity syndrome (toxidrome) elicited by 5-hydroxy-l-tryptophan in clorgyline-pretreated rats | volume=588 | issue=2–3 | pages=198–206 | date=7 July 2008 | issn=0014-2999 | doi=10.1016/j.ejphar.2008.04.004}}</ref><ref name="two">{{cite journal | vauthors=((Izumi, T.)), ((Iwamoto, N.)), ((Kitaichi, Y.)), ((Kato, A.)), ((Inoue, T.)), ((Koyama, T.)) | journal=European Journal of Pharmacology | title=Effects of co-administration of a selective serotonin reuptake inhibitor and monoamine oxidase inhibitors on 5-HT-related behavior in rats | volume=532 | issue=3 | pages=258–264 | date=27 February 2006 | issn=0014-2999 | doi=10.1016/j.ejphar.2005.12.075}}</ref>
*'''[[DangerousInteraction::Serotonin releasers]]''' such as '''[[MDMA]]''', '''[[4-FA]]''', '''[[MDAI]]''' and '''[[αMT]]''' - To prevent serotonin syndrome, 5-HTP should only be taken once the user has come down from the MDMA (or other serotonin releaser), roughly 12 hours after the last dose.
*'''[[DangerousInteraction::SNRIs]]'''
*'''[[DangerousInteraction::Serotonin releasers]]''' such as '''[[MDMA]]''', '''[[mephedrone]]''', '''[[4-FA]]''', '''[[MDAI]]''' and '''[[αMT]]''' - To prevent serotonin syndrome, 5-HTP should only be taken once the user has come down from the MDMA (or other serotonin releaser), roughly 12 hours after the last dose.
*'''[[DangerousInteraction::MAOIs]]''' such as '''[[syrian rue]]''', '''[[banisteriopsis caapi]]''', '''[[2C-T-2]]''', '''[[2C-T-7]]''', '''[[αMT]]''', and some '''[[antidepressants]]''' - When combined with antidepressants of the MAOI class, high doses of 5-HTP can cause acute serotonin syndrome in rats.<ref name="one" /><ref name="two" />
*'''[[DangerousInteraction::MAOIs]]''' such as '''[[syrian rue]]''', '''[[banisteriopsis caapi]]''', '''[[2C-T-2]]''', '''[[2C-T-7]]''', '''[[αMT]]''', and some '''[[antidepressants]]''' - When combined with antidepressants of the MAOI class, high doses of 5-HTP can cause acute serotonin syndrome in rats.<ref name="one" /><ref name="two" />
5-HTP is commonly sold over the counter as a dietary supplement in the United States, United Kingdom, and Canada and is not subject to any illicit substance control laws.{{citation needed}}
5-HTP is commonly sold over the counter as a dietary supplement in the United States, United Kingdom, Canada and most of Europe and is not subject to any illicit substance control laws.
In some parts of Europe, where it prescribed as an antidepressant, there may be some controls on its sale and distribution.{{citation needed}}
In some parts of Europe, where it prescribed as an anti-depressant, there may be some controls on its sale and distribution.{{citation needed}}
WARNING: Always start with lower doses due to differences between individual body weight, tolerance, metabolism, and personal sensitivity. See responsible use section.
DISCLAIMER: PW's dosage information is gathered from users and resources for educational purposes only. It is not a recommendation and should be verified with other sources for accuracy.
5-Hydroxytryptophan (also known as 5-HTP and oxitriptan) is a naturally occurring chemical substance and a metabolic intermediate in the biosynthesis of serotonin in the human body.[citation needed]
5-HTP is available over the counter in the United States, United Kingdom, and Canada as a dietary supplement and is sometimes used as an antidepressant, sleep aid, and appetite suppressant. It is marketed in some European countries as a prescription drug for the treatment of major depression.[1]
5-HTP is also popularly consumed by users of MDMA and other serotonin-releasing agents to try to reduce the negative after effects that begin during the substance's come down period, including anxiety, depression, and cognitive fatigue.[2]
Since 5-HTP is a precursor for the neurotransmitter serotonin and MDMA administration both depletes serotonin levels in the brain as well as inhibit the enzyme needed to produce it (i.e. tryptophan hydroxylase) for a short period after,[3] it is believed that taking 5-HTP in the days after coming down will speed up the production of serotonin and decrease the time needed to recover (though there are many popular misconceptions and controversies as to just how effective it is for this purpose).[citation needed]
5-HTP should not be taken until 12 hours after one's last dose of MDMA because combining the two substances could interact to increase the brain's serotonin levels to dangerous levels, which can result in a potentially life-threatening condition called serotonin syndrome.
5-HTP or 5-Hydroxytryptophan is a synthetic indole alkaloid molecule of the tryptamine class. Tryptamines share a core structure comprised of a bicyclic indole heterocycle attached at R3 to an amino group via an ethyl side chain. 5-HTP is substituted at R5 of its indole heterocycle with a hydroxy (OH) functional group. It also contains propanoic acid group bound to the terminal amine RN of its tryptamine backbone. 5-HTP is the 5-hydroxy analog of tryptophan, and is sold in its levorotary isomer form. 5-HTP contains the core structure of serotonin with the addition of a propanoic acid at RN, and is converted by the body into serotonin by metabolic reactions.
Pharmacology
The psychoactive action of 5-HTP is derived from its increase in production of serotonin in central nervous system tissue. 5-HTP is decarboxylated to serotonin (5-hydroxytryptamine or 5-HT) by the enzyme 'aromatic-L-amino-acid decarboxylase', with the help of vitamin B6.[4] This reaction occurs both in nervous tissue and in the liver.[5] 5-HTP crosses the blood–brain barrier, while 5-HT (serotonin) does not.[6]
Excess 5-HTP, especially when administered with vitamin B6, is thought to be metabolized and excreted.[7][8]
Cognitive euphoria - Although mild, this effect is present at heavier dosages, but may also come with it a number of peripheral side effects due to peripheral serotonin activity (mostly on the gut).
Due to the conversion of 5-HTP into serotonin by the liver, with prolonged use, there may be a significant risk of heart valve disease from serotonin's effect on the heart, which is thought to be due to agonism of the 5-HT2B receptors present on it.[9][10]
It has been suggested that 5-HTP may cause eosinophilia-myalgia syndrome (EMS), a serious condition which results in extreme muscle tenderness, myalgia, and blood abnormalities. However, there is evidence to show that EMS was likely caused by a contaminant in certain 5-HTP supplements instead of the substance itself.[11]
Dangerous interactions
Although many substances are safe on their own, they can become dangerous and even life-threatening when combined with other substances. The list below contains some common potentially dangerous combinations, but may not include all of them. Certain combinations may be safe in low doses of each, but still increase the potential risk of death. Independent research should always be done to ensure that a combination of two or more substances is safe before consumption.
Combinations in the list below may increase the amount of neurotransmitters, such as serotonin, to dangerous or even fatal levels, resulting in life-threatening serotonin syndrome.
SSRIs - When combined with antidepressants of the SSRI class, high doses of 5-HTP can cause acute serotonin syndrome in rats.[12][13]
SNRIs
Serotonin releasers such as MDMA, mephedrone, 4-FA, MDAI and αMT - To prevent serotonin syndrome, 5-HTP should only be taken once the user has come down from the MDMA (or other serotonin releaser), roughly 12 hours after the last dose.
5-HTP is commonly sold over the counter as a dietary supplement in the United States, United Kingdom, Canada and most of Europe and is not subject to any illicit substance control laws.
In some parts of Europe, where it prescribed as an anti-depressant, there may be some controls on its sale and distribution.[citation needed]
↑Rahman, M. K., Nagatsu, T., Sakurai, T., Hori, S., Abe, M., Matsuda, M. (October 1982). "Effect of pyridoxal phosphate deficiency on aromatic L-amino acid decarboxylase activity with L-DOPA and L-5-hydroxytryptophan as substrates in rats". Japanese Journal of Pharmacology. 32 (5): 803–811. doi:10.1254/jjp.32.803. ISSN0021-5198.
↑Bouchard, S., Bousquet, C., Roberge, A. G. (September 1981). "Characteristics of dihydroxyphenylalanine/5-hydroxytryptophan decarboxylase activity in brain and liver of cat". Journal of Neurochemistry. 37 (3): 781–787. doi:10.1111/j.1471-4159.1982.tb12555.x. ISSN0022-3042.
↑Nakatani, Y., Sato-Suzuki, I., Tsujino, N., Nakasato, A., Seki, Y., Fumoto, M., Arita, H. (May 2008). "Augmented brain 5-HT crosses the blood-brain barrier through the 5-HT transporter in rat". The European Journal of Neuroscience. 27 (9): 2466–2472. doi:10.1111/j.1460-9568.2008.06201.x. ISSN1460-9568.
↑Amamoto, T., Sarai, K. (September 1976). "On the tryptophan-serotonin metabolism in manic-depressive disorders. Changes in plasma 5-HT and 5-HIAA levels and urinary 5-HIAA excretion following oral loading of L-5HTP in patients with depression". Hiroshima Journal of Medical Sciences. 25 (2–3): 135–140. ISSN0018-2052.
↑Gustafsson, B. I., Tømmerås, K., Nordrum, I., Loennechen, J. P., Brunsvik, A., Solligård, E., Fossmark, R., Bakke, I., Syversen, U., Waldum, H. (29 March 2005). "Long-term serotonin administration induces heart valve disease in rats". Circulation. 111 (12): 1517–1522. doi:10.1161/01.CIR.0000159356.42064.48. ISSN1524-4539.
↑Xu, J., Jian, B., Chu, R., Lu, Z., Li, Q., Dunlop, J., Rosenzweig-Lipson, S., McGonigle, P., Levy, R. J., Liang, B. (December 2002). "Serotonin mechanisms in heart valve disease II: the 5-HT2 receptor and its signaling pathway in aortic valve interstitial cells". The American Journal of Pathology. 161 (6): 2209–2218. doi:10.1016/S0002-9440(10)64497-5. ISSN0002-9440.
↑Michelson, D., Page, S. W., Casey, R., Trucksess, M. W., Love, L. A., Milstien, S., Wilson, C., Massaquoi, S. G., Crofford, L. J., Hallett, M. (December 1994). "An eosinophilia-myalgia syndrome related disorder associated with exposure to L-5-hydroxytryptophan". The Journal of Rheumatology. 21 (12): 2261–2265. ISSN0315-162X.
↑ 12.012.1Ma, Z., Zhang, G., Jenney, C., Krishnamoorthy, S., Tao, R. (7 July 2008). "Characterization of serotonin-toxicity syndrome (toxidrome) elicited by 5-hydroxy-l-tryptophan in clorgyline-pretreated rats". European Journal of Pharmacology. 588 (2–3): 198–206. doi:10.1016/j.ejphar.2008.04.004. ISSN0014-2999.
↑ 13.013.1Izumi, T., Iwamoto, N., Kitaichi, Y., Kato, A., Inoue, T., Koyama, T. (27 February 2006). "Effects of co-administration of a selective serotonin reuptake inhibitor and monoamine oxidase inhibitors on 5-HT-related behavior in rats". European Journal of Pharmacology. 532 (3): 258–264. doi:10.1016/j.ejphar.2005.12.075. ISSN0014-2999.
