Could 5-HTP Really Help You Lose Weight?

Could 5-HTP Really Help You Lose Weight?

When you’re starting a weight cut or wanting to shed a few pounds for a big event, you want to make sure you’ve got every angle covered. And that means not only planning your workouts, but your diet too.

You’re here because you’re doing your research on effective weight loss supplements – and when it comes to 5-HTP, it’s a supplement that comes up every now and then.

Is it one you should add to your stack?

In this article we let you in on everything you need to know. In short, you’ll learn the following:

  • What is 5-hydroxytryptophan?
  • What is it used for?
  • Can 5-HTP help you lose weight?
  • Is it safe?
  • Are there better alternatives?

What is 5-HTP?

5-hydroxytryptophan (5-HTP) is a metabolite of the amino acid L-tryptophan.

It is found in the pods of the West African plant Griffonia simplicifoliabut is also produced in the body as well.

5-HTP is best known as an immediate precursor to serotonin – it converts directly to the neurotransmitter in your brain. How? Via an enzyme called L-amino acid decarboxylase. 

Dietary sources of tryptophan such as pineapples, turkey and salmon only boost 5-HTP levels by a small amount, whereas some medications and supplements have been shown to elevate levels of the metabolite much higher.

How Does 5-HTP Work?

As we know, 5-HTP acts on your nervous system to increase the production of serotonin.

As an important regulator of mood and happiness, the neurotransmitter serotonin is important for overall wellness and health. It is responsible for controlling important functions such as:

  • Sleep
  • Cardiovascular and muscular function
  • Temperature regulation
  • Mood

Because serotonin is so closely linked to mood and well-being, it has a long clinical history as a treatment mental health conditions. These include low mood, clinical depression, anxiety and insomnia. It has also been used to treat cerebellar ataxia, fibromyalgia and hyperactivity too.

And although its clinical profile lies more in overall health, 5-HTP as a supplement has recently been proposed as a possible weight loss aid. 

Read on to find out why…

5-HTP and Weight Loss – Is There a Connection?

In order to lose weight you need to achieve a calorie deficit. This means that you need to consistently eat less calories than you burn off each day.

When you achieve a deficit, your fat cells release energy in order to help you get through the day – and the result is of course that you begin to gradually lose fat.

Once you are in a calorie deficit, using fat burner supplements that increase thermogenesis, elevate fat oxidation and increase calorie burn help to speed the process up.

5-HTP may increase calorie intake

5-HTP isn’t a direct fat burner because it doesn’t increase your metabolic rate or help you burn more calories. But there is a very small amount of evidence that shows it may reduce food intake – but only by a modest amount.

For example, a study published in the International Journal of Obesity and Related Metabolic Disorders [1] found that supplementing 750 mg of 5-HTP per day for 2 weeks in a group of overweight men and women led to a minor decrease in body weight. 

Similar results were seen with a much larger dose of 900 mg per day for a particularly long period of 12-weeks led to weight loss in a group of obese women [2]. The loss of mass was attributed to a reduction in food intake rather than a direct mechanism.

Key Point: The reduction in weight from 5-HTP is only secondary to a slightly reduced appetite – and even then, the results aren’t groundbreaking.

Are There Any Side Effects?

The safety and effectiveness of 5-HTP is still under investigation.

One thing that is concerning is that whilst the studies above used high doses of 750-900 mg, it is still recommended that normal doses remain within a 300 mg threshold until further research is conducted [3]. This of course means it’s less likely to be effective as a weight loss drug if you take a high dose; and more likely to be dangerous if you take a higher dose.

To date there haven’t been any cases of severe side effects or adverse reactions, but the following have been reported:

  • Heartburn, nausea and diarrhoea
  • Gas, bloating and stomach upset

In terms of taking 5-HTP as a weight loss aid – there does seem to be a higher frequency of nausea reported when compared to placebo when appetite is suppressed [1]. This does tend to subside within a few weeks though.

Drug interactions

There may however be an interaction between 5-HTP and other medications. These can lead to potentially more severe side effects if not monitored.

If you are taking selective serotonin reuptake inhibitors (SSRIs), antidepressantsmigraine medications or use illicit drugs you need to check with your health professional before taking the serotonin precursor.

Summary – Should You Use 5-HTP for Weight Loss?

As a precursor to serotonin, 5-HTP seems to be reasonably well suited to treating anxiety and depression. It may have a secondary effect on weight loss by helping you to reduce food intake, but even then, the results aren’t currently convincing.

We suggest that if you are looking for an effective supplement to help you improve your body composition and shred fat you focus your attention on nutrients that have a primary action on fat loss as well as helping to curb your appetite.

Instant Knockout

Not only does Instant Knockout contain the appetite-reducing nutrient glucommanan, it also contains ingredients that act directly on fat loss too.

So if you’re wanting to shred fat, boost energy and ramp up your workout productivity then this is the supplement for you.

  • Effective for Fat Loss – Chisel off the fat, and bring out those sculpted abs
  • Increase Energy Levels – Workout harder, for longer
  • Cut down on Cravings – Consume less calories, feel more full
  • Increase Muscle Definition – Get that ‘complete’ physique look

As a premium-brand fat burner, Instant Knockout is the favoured supplement of MMA fighters that want to drop fat fast. It delivers powerful results in a safe and drug-free way.


  1. Canqiano,C et al. Effects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patients. Int J Obes Relat Metab Disord. 1998; 22(7): 648-54
  2. Canqiano, C et al. Eating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophan. Am J Clin Nutr. 1992; 56(5): 863-7
  3. Turner, EH et al. Serotonin a la carte: supplementation with the serotonin precursor 5-hydroxytryptophan. Pharmacol Ther. 2006; 109(3): 325-38