Summary
This article explains whether L-tryptophan or 5-HTP can be safely taken with SSRI antidepressants. It clarifies that blood serotonin levels are not related to depression and warns about the risk of serotonin syndrome when combining these substances.
Question
I hope you’re well. I have an appointment with you soon, but I believe it’s important to ask you about this beforehand, as it might affect my treatment.
I went to see an integrative doctor recommended by a friend. She ordered a series of lab tests. I would like to consult you regarding the results shown on page 7, as the serotonin levels came out very low. According to what the doctor told me, the antidepressant might not be working properly due to my low serotonin levels. Based on these results, among other things, she prescribed me 5-HTP (one capsule each night at 10 p.m.) to increase serotonin, and also recommended an injected tryptophan infusion, which I will receive this Friday at her clinic.
My question is whether following her recommendation is safe or what you would advise instead.
I look forward to your response and thank you very much.
Answer:
Dear X,
I’m really glad you decided to consult me before moving forward.
First, I’d like to clarify that blood serotonin levels have NO proven connection with depression (having low serotonin levels in the blood is not linked to the appearance of low mood symptoms). In medicine, blood levels are currently used only to detect certain types of cancer that produce this substance (serotonin), so if the levels are elevated, it might indicate the presence of a tumor, something that has nothing to do with elevated mood, and in fact, could be a risk factor for depression.
However, what concerns me most is that L-tryptophan should NOT be combined with antidepressants from the SSRI family, as this significantly increases the risk of Serotonin Syndrome (a very unpleasant and potentially life-threatening adverse reaction).
It’s interesting because if we say that depression is related to low serotonin levels in the brain (NOT in the blood), one might think that taking supplements of the amino acid the body uses to «produce» serotonin could help. But instead, it can lead to an excessive increase in serotonin levels and subsequent toxicity.
If you decide to go ahead with the treatment this professional is suggesting, you should first completely discontinue Sertraline.
Other antidepressants in the SSRI family that should not be taken with L-tryptophan include: fluoxetine, fluvoxamine, paroxetine, and escitalopram.
Here are some trusted scientific links for more information on both topics:
https://medlineplus.gov/spanish/ency/article/003562.htm
https://www.msdmanuals.com/es/professional/lesiones-y-envenenamientos/enfermedades-por-calor/s%C3%ADndrome-serotonin%C3%A9rgico?ruleredirectid=756
https://medlineplus.gov/spanish/druginfo/natural/326.html
Frequently Asked Questions (FAQ)
1. Do low blood serotonin levels indicate depression?
No. There is no scientific evidence linking blood serotonin levels to depressive symptoms.
2. Is it safe to take L-tryptophan or 5-HTP with antidepressants?
No. Combining them with SSRI antidepressants increases the risk of serotonin syndrome.
3. What is serotonin syndrome?
A serious adverse reaction caused by excessive serotonin, which can be potentially life-threatening.
4. Which antidepressants should not be combined with L-tryptophan?
SSRIs such as sertraline, fluoxetine, fluvoxamine, paroxetine, or escitalopram.
5. Should I consult a professional before taking natural supplements?
Yes. Supplements can interact with medication and should always be reviewed by a healthcare professional.
Division of Medicine
Director of SINEWS MTI
Founding Partner
Psychiatrist
Children, adolescents and adults
Languages: English and Spanish