- Nausea
- Vomiting
- Stomach Upset
- Cramps
- Nightmares
- Sleep Disturbance
In reality, you don't need to worry as much about the side-effects of 5-htp as you do about the side-effects from SSRI's such as Prozac and Celexa. Although the list may look similar to the one you find on an anti-depressant packet generally people feel the side-effects from 5-htp much more mildly. Some people do not feel any side-effects at all and only get benefits.
It should also be noted that side-effects from 5-htp are normally seen in people who supplement more than 100mg a day. If you start off on a low dose and work your way up slowly to the dose you need, you will be able to see how 5-htp effects you without taking too much. At any rate, at a dose of 100mg or less, in the vast majority of cases any side-effects will be mild and should disappear soon after discontinuation of 5-HTP.
There is one side-effect however that is potentially more damaging and more problematic. 5-HTP can convert to the neurotransmitter Serotonin prematurely. This conversion happens in the liver and causes much higher levels than normal of Serotonin in the bloodstream. This wayward Serotonin can potentially damage heart valves. This risk has not been proven to be true and it might just be a case of the pharmaceutical industry spreading malicious rumors to stop their precious patented drugs becoming less profitable.
Given the lack of research in this field all we can do is suggest talking to your doctor and making sure you take the least dose possible. Also, keep an eye on any updates and have regular check-ups.