Best tryptophan supplement

Patrick Farmer

Tryptophan supplements boost your brain’s production of serotonin and melatonin, essential for healthy sleep and mood regulation.

Which tryptophan supplement is best?

Tryptophan is an essential amino acid that’s naturally found in foods such as eggs, tofu and poultry. It plays an important role in the production of serotonin and could be useful as a sleep aid for people who live with insomnia. Because of this, many want to add tryptophan to their supplement regimen. 

Most tryptophan supplements are sold as capsules, but you can also buy it in powder or even gummy form. Now Foods L-Tryptophan Capsules are the top pick because they’re potent and vegan-friendly. 

What to know before you buy a tryptophan supplement

Benefits of tryptophan

Tryptophan is primarily taken as a sleep support supplement. When combined with a healthy diet, it helps increase the production of both serotonin and melatonin in the brain. Both of these molecules have the potential to improve the quality of your sleep, according to the National Institutes of Health. Serotonin is closely tied to improved mood and anxiety reduction, the NIH says, while melatonin is associated with your body’s circadian rhythm, otherwise known as the sleep-wake cycle. Other research has shown that a deficiency of tryptophan may be connected with anxiety and depression in some people.

Side effects

As with most supplements, taking tryptophan in supplement form could cause some adverse side effects. They’re fairly uncommon, but some users have experienced nausea, dry mouth and diarrhea after taking tryptophan supplements. It can cause drowsiness in high doses, and there’s the risk of raising your serotonin levels too much, particularly if you already take an antidepressant. 

Tips for improving sleep

  • Stay away from devices in the evening. Smartphones and laptops produce blue light, which can interfere with your brain’s production of melatonin and keep you awake. 
  • Get lots of sunlight during the day. This will keep your circadian rhythm natural and healthy. 
  • Avoid caffeinated beverages such as coffee or tea in the afternoon or evening. 
  • Avoid alcohol before bedtime, as it can negatively impact your melatonin production and interfere with sleep. 
  • Consider taking natural supplements such as valerian root, magnesium or lavender If you’re dealing with acute insomnia. 

What to look for in a quality tryptophan supplement


Like all supplements, tryptophan capsules aren’t regulated by the Food and Drug Administration. To verify the quality of the supplement, look for third-party certifications on the packaging. The United States Department of Agriculture — or USDA — may certify ingredients as organic, while organizations such as Vegan Action can confirm that a supplement contains no animal byproducts. 


Some supplements incorporate additional botanicals and chemical compounds known for improving sleep. L-theanine is another amino acid the NIH says improves sleep quality, while plants such as valerian root have been used to promote restful sleep for thousands of years. Blends are often used in herbal teas and sleep gummies, supplements that are commonly used by people who don’t enjoy taking pills.   


To improve sleep, most manufacturers recommend taking 500-1,000 milligrams of tryptophan two to three times a day on an empty stomach. Look closely at the supplement’s product details for specific dosing instructions. 

How much you can expect to spend on a tryptophan supplement

The cost of a tryptophan supplement usually depends on its potency and any other active ingredients. For most, expect to pay around $5-$25 for a bottle of capsules. 

Tryptophan supplement FAQ

Does tryptophan interact with any medications? 

A. A tryptophan supplement may interact with other drugs that affect your serotonin levels, such as most antidepressants. It could also interact with migraine medications and some cough medicines. To be safe, talk with your doctor before taking any supplements, particularly if you’ve been prescribed any medications. 

Does the tryptophan in turkey make you sleepy? 

A. A popular myth in North America is that the tryptophan in cooked turkey is what makes you feel sleepy after Thanksgiving dinner. The reality is that there isn’t enough tryptophan in turkey to make you feel drowsy. Instead, it is believed that the long day of cooking and overindulgence in carb-heavy food are more to blame for post-dinner sleepiness. 

What’s the best tryptophan supplement to buy?

Top tryptophan supplement

Now Foods L-Tryptophan Capsules

Now Foods L-Tryptophan Capsules

What you need to know: This supplement is entirely plant-based and backed by a leading brand name. 

What you’ll love: It’s friendly for vegans and vegetarians, and it contains no genetically modified organisms. Each capsule contains 500 milligrams of the essential amino acid. The company has been producing high-quality and affordable supplements since 1968.

What you should consider: Some users may want a higher dosage. 

Where to buy: Sold by iHerb

Top tryptophan supplement for the money

Source Naturals L-Tryptophan Capsules

Source Naturals L-Tryptophan Capsules

What you need to know: These capsules are very affordable and easy to swallow. 

What you’ll love: Users note an almost immediate improvement in sleep quality after taking these supplements. A single serving provides 1.5 grams of tryptophan. The ingredients found in the supplement undergo rigorous testing to ensure quality and potency. 

What you should consider: This isn’t suitable for vegans, and it’s not clear if the ingredients are certified organic. 

Where to buy: Sold by iHerb

Worth checking out

Life Extension Optimized Tryptophan Plus

Life Extension Optimized Tryptophan Plus 

What you need to know: This supplement contains a generous amount of tryptophan, alongside additional nutrients that make the amino acid more effective. 

What you’ll love: The vegetarian capsules are certified to be free of gluten and GMOs, and the unique formula contains crucial nutrients such as niacin and lysine alongside botanicals like hops extract to improve sleep. 

What you should consider: The capsules are a bit larger than some users prefer. 

Where to buy: Sold by iHerb


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Patrick Farmer writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.