Derived from the amino acid tryptophan, 5-HTP is a precursor to serotonin, a neurotransmitter that plays a crucial role in regulating mood and appetite. While some studies suggest a potential link between 5-HTP and weight loss, it's important to understand both the benefits and risks associated with its use.
How Does 5-HTP Affect Weight Loss?
The role of serotonin in appetite control
Serotonin is known to have an impact on appetite regulation. Low serotonin levels are often associated with increased cravings and overeating, while higher serotonin levels can lead to reduced food intake and a feeling of satiety.  As a precursor to serotonin, 5-HTP has been theorized to enhance serotonin levels and potentially aid in weight loss by suppressing appetite and promoting feelings of fullness.
5htp self reported appetite control
Furthermore, 5-HTP intake has been shown to result int increased feelings of early satiety  and appetite inhibition in clinical trials.
With participants reporting reduced feelings of hunger and less cravings for unhealthy foods (this has been backed up by placebo and brain scan trials which we'll come onto later). These effects may be attributed to the activation of regions involved in satiation, such as the left lingual gyrus (LG) and cingulate cortex. The increased activity in these regions may help individuals feel more satisfied with smaller food portions, leading to reduced calorie intake and weight loss. 
Clinical trials and weight loss results
Several clinical trials have investigated the effects of 5-HTP on weight loss. A study conducted by Cangiano et al. in 1992 examined the impact of 5-HTP supplementation on obese patients.  The researchers found that patients who received 300 mg of 5-HTP per day experienced significant weight loss during both a period without dietary restrictions and a period with a prescribed low-calorie diet. These findings suggest that 5-HTP may play a role in promoting weight loss, especially when combined with dietary measures.
Functional magnetic resonance imaging (fMRI) study on 5htp
In one study, participants were given either 5-HTP or a control substance and then exposed to various food stimuli.
The 5-HTP group showed increased activation in regions associated with reward processing, such as the ventromedial prefrontal cortex (VMPFC), dorsolateral prefrontal cortex (DLPFC), and limbic regions.
These findings suggest that 5-HTP may enhance the brain's response to food, leading to a more pronounced activation of regions involved in food evaluation and reward. 
Macronutrient Preferences and 5-HTP
Macronutrients, such as proteins, carbohydrates, and fats, play a crucial role in our dietary choices. Studies have shown that 5-HTP intake can influence macronutrient preferences. The 5-HTP group demonstrated increased activity in response to protein-rich foods, particularly in regions associated with reward processing, such as the caudate and putamen. This suggests that 5-HTP may enhance the brain's preference for protein-rich foods.
In contrast, the control group showed greater responsiveness to high-calorie and carbohydrate-rich foods, indicating a preference for these types of foods. This finding aligns with previous research showing that individuals with higher serotonin levels tend to have a reduced appetite for carbohydrates and fats. The differential brain responses to macronutrients in the 5-HTP and control groups highlight the potential role of serotonin in modulating food preferences.
Reduction in carbohydrate intake
In addition to weight loss, the study by Cangiano et al. also reported a reduction in carbohydrate intake among the participants who received 5-HTP.
This finding suggests that 5-HTP supplementation may influence macronutrient selection by decreasing the preference for carbohydrate-rich foods. By reducing carbohydrate consumption, individuals may be able to better manage their calorie intake and support their weight loss efforts. 
How Does 5htp Work For Weight Loss
5-HTP works by increasing the levels of serotonin in the brain. Serotonin is involved in various physiological processes, including mood regulation, appetite control, and sleep patterns. When taken as a supplement, 5-HTP is believed to bypass the need for the body to convert tryptophan into 5-HTP, allowing for a more direct increase in serotonin levels. By enhancing serotonin production, 5-HTP may exert its potential benefits on weight loss, sleep, and mood.
The Safety of 5-HTP for Weight Loss
While 5-HTP shows promise as a weight loss aid, it's crucial to consider the potential risks and side effects associated with its use.
Gastrointestinal upset and other side effects
During clinical trials, some individuals taking large amounts of 5-HTP experienced gastrointestinal upset, including nausea and potential headaches, sleepiness, and muscle pain. However, it's important to note that these side effects were relatively uncommon. The majority of participants tolerated 5-HTP well, with only a small percentage reporting adverse effects. 
If you have gastrointestinal issues or are pregnant, breastfeeding, or taking antidepressant medications, it's crucial to consult with a healthcare professional before using 5-HTP.
Furthermore, it's important to select a reputable brand that offers pure 5-HTP without any additives, fillers, or binders. Impurities or contaminants in 5-HTP supplements can pose health risks.
How to Take 5-HTP
The appropriate dosage of 5-HTP can vary depending on individual needs and health conditions. It's important to follow the recommended dosage instructions provided by the manufacturer or as advised by a healthcare professional. Starting with a lower dosage and gradually increasing it may help assess individual tolerance and minimize the risk of side effects.
5htp Dosage For Weight Loss
It's important to note that the optimal dosage for specific benefits, such as weight loss or sleep improvement, has not been firmly established, and further research is needed in this regard. However, generally speaking a minimum of 100mg is recommend, and raising your dosage as needed. It has been trialled as safe in doses of up to 900mg/day, although these were only short term trials.
Other Benefits of 5HTP
Improved Sleep Quality
Getting a good night's sleep is essential for overall well-being, and 5-HTP may offer potential benefits in this area. Animal studies have shown that 5-HTP supplementation can enhance sleep quality and duration, indicating its role in promoting restful sleep. While more research is needed to establish its effectiveness in humans, 5-HTP may be particularly helpful for individuals experiencing sleep disorders or disturbances, such as sleep terrors and sleepwalking. 
Serotonin, often referred to as the "happiness hormone," plays a crucial role in regulating mood. As 5-HTP increases serotonin levels in the brain, it has the potential to improve mood and alleviate symptoms of depression. However, it's important to note that the research on 5-HTP as a treatment for depression is limited, and more high-quality studies are needed to draw definitive conclusions. If you are considering using 5-HTP for mood enhancement, it's essential to consult with a healthcare professional to ensure it is safe and appropriate for your specific situation. 
Does 5htp Help You Lose Weight?
In conclusion, 5-HTP appears to modulate the brain's response to food stimuli, influencing macronutrient preferences and potentially aiding weight loss efforts. By enhancing the brain's reward and satiation pathways, 5-HTP may promote healthier food choices and reduce calorie intake.
1 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8243944/
2 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7796270/
3 - https://pubmed.ncbi.nlm.nih.gov/1384305/
4 - https://pubmed.ncbi.nlm.nih.gov/1384305/
5 - https://pubmed.ncbi.nlm.nih.gov/28127513/
6 - https://pubmed.ncbi.nlm.nih.gov/9705024/
7 - https://pubmed.ncbi.nlm.nih.gov/9727088/
8 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8181734/
9 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC257800/