5-Hydroxytryptophan, better known as 5-HTP, is a natural supplement that claims to control appetite, improve insomnia, relieve headaches, and boost and balance mood. But what exactly is this strange-sounding substance and does it really deliver on its promises?
What is 5-HTP?
5-HTP is a naturally occurring amino acid used by the human body to make serotonin, the neuro-transmitter known as the ‘happy hormone’ that appears to play a key role in sleep, moods, pain control, inflammation and other bodily functions. 5-HTP is manufactured by the body from l-tryptophan, an amino acid found in most dietary proteins. However, eating l-tryptophan-containing foods does not significantly raise 5-HTP levels. The 5-HTP used in supplements is derived from the seeds of the West African medicinal plant, Griffonia simplicifolia.
What does 5-HTP do?
Scientific studies suggest that 5-HTP may be beneficial for a range of different conditions, particularly those linked to serotonin imbalance and dysfunction such as depression, fibromyalgia and migraines. It acts by boosting levels of serotonin within the central nervous system (CNS) as well as other neurotransmitters and CNS chemicals such as melatonin, dopamine and norepinephrine. This action allows 5-HTP to have significant effects on brain chemistry and on serotonin-related conditions.
- Depression. 5-HTP can markedly improve symptoms of depression, according to several clinical trials. In one involving 36 patients with diagnosed depression, 5-HTP (100 mg three times a day) was tested against the selective serotonin reuptake inhibitor (SSRI) fluvoxamine (150 mg three times a day) for six weeks. The results showed that both treatment groups had significant and nearly equal reductions in depression beginning at week two and continuing through to week six. By week four, 15 of the 36 patients (42 per cent) treated with 5-HTP, and 18 of the 33 patients (55 per cent) treated with fluvoxamine had improved by at least 50 per cent, according to a standard depression rating scale. By the end of the study, the two groups had nearly equal numbers showing 50-per-cent improvement, but there were more treatment failures in the fluvoxamine group (Altern Med Rev, 1998; 3: 271-80). 5-HTP at a dose of 200-300 mg/day might also be useful for treating depressive symptoms in patients with bipolar disorder (J Affect Disord, 1980; 2: 137-46; Acta Psychiatr Scand Suppl, 1981; 290: 191-201).
- Fibromyalgia. In a double-blind, placebo-controlled trial of 50 patients with this chronic pain condition, 100 mg of 5-HTP three times a day for a month led to significant improvements in all of the symptoms studied, including pain, tender points, morning stiffness, sleep disturbances, anxiety and fatigue (J Int Med Res, 1990; 18: 201-9). A longer-term (90-day) trial by the same researchers reported similar findings (J Int Med Res, 1992; 20: 182-9).
- Migraines and headaches. 5-HTP appears to be effective for the prevention of chronic headaches of various types, including migraines, tension headaches and headaches in children (Altern Med Rev, 1998; 3: 271-80). In a study of 124 patients, 5-HTP was pitted against methysergide, one of the more commonly used migraine drugs. After six months, a significant improvement was observed in 75 per cent of the patients treated with methysergide and in 71 per cent of the cases treated with 5-HTP. However, 5-HTP was more successful at reducing the intensity and duration of migraine attacks rather than their frequency, the researchers said (Eur Neurol, 1986; 25: 327-9). Nonetheless, another study of 48 elementary and junior-high-school students found that treatment with 5-HTP (4.5 mg/kg/ day) resulted in a 70-per-cent decrease in headache frequency compared with an 11-per-cent decrease with a placebo (Drugs Exp Clin Res, 1987; 13: 425-33).
- Insomnia. Some studies suggest that 5-HTP might be helpful for sleep disorders such as insomnia. Giving 600 mg in divided doses to healthy participants was found to increase the amount of rapid eye movement (REM) sleep, an indication of improvement in sleep quality. A smaller dose might be better, however, as higher doses could cause nightmares, according to anecdotal reports. A study using a 200-mg dose of 5-HTP showed that even this amount can increase REM sleep, albeit not as much as did the larger dose (Altern Med Rev, 1998; 3: 271-80).
- Obesity. 5-HTP is often found in weight-loss supplements with claims that it can curb appetite and help to shed the pounds. There is some evidence to support this, including three trials in obese patients showing reduced food intakes and subsequent weight loss with 5-HTP supplementation (Altern Med Rev, 1998; 3: 271-80). In one double-blind trial, 20 obese patients were randomly assigned to receive either 900 mg/day of 5-HTP or a placebo for two consecutive six-week periods. No diet was prescribed during the first period, and a diet restricted to 5040 kJ/day was recommended for the second six-week period. The researchers reported significant weight loss in the 5-HTP group for both periods, as well as a reduction in carbohydrate intake and a “consistent presence of early satiety”. The downside was that 80-per-cent of those taking 5-HTP experienced nausea; this, however, was not severe enough to cause anyone to drop out, and it diminished over the course of the study (J Clin Nutr 1992; 56: 863-7).
What are the risks?
Side-effects of 5-HTP are generally mild, and may include nausea, heartburn, gas, feelings of fullness and rumbling gastrointestinal sensations in some people. At high doses, however, it is possible that serotonin syndrome-having too much serotonin in the body-could develop. This might also arise if the supplement is taken in combination with an antidepressant drug such as an SSRI, although no specific reports of such drug interactions have been published so far (Altern Med Rev, 1998; 3: 271-80).
Another concern is that 5-HTP could lead to eosinophilia-myalgia syndrome (EMS), a serious condition resulting in extreme muscle tenderness, muscle pain and blood abnormalities (Adv Exp Med Biol, 1999; 467: 461-8). However, there is evidence to show that EMS was due to a contaminant in early 5-HTP supplements, before the introduction of the current, more stringent, manufacturing practices (J Rheumatol, 1994; 21: 2261-5).
Future prospects
5-HTP is showing promise in a number of chronic conditions, and may well prove to be a useful alternative to drugs such as SSRIs and migraine preventers. However, the studies so far are small, and there appears to be a lack of more recent research on the supplement. There are also some question marks surrounding safe dosages and manufacturing standards.
If you do wish to try 5-HTP, make sure you do so under the supervision of a medical professional.
Joanna Evans
WDDTY ISSUE 22 NO.9, NOV. 2011
