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Source Naturals, L-Tryptophan, 500 mg, 120 Tablets

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In Stock
  • Expiration Date: Sep 2020
  • Shipping Weight: 0.3 lbs (0.14 kg)
  • Product Code: SNS-01980
  • UPC Code: 021078019800
  • Package Quantity: 120 Tablets
  • Dimensions: 2.2 x 2.2 x 4 in, 0.25 lbs (0.11 kg)
Product Overview


  • Dietary Supplement
  • Mood, Relaxation, Sleep
  • Non-GMO Validated

The essential amino acid L-tryptophan helps support relaxation, restful sleep, and feeling better. It plays a part in the synthesis of both melatonin and serotonin, hormones involved with mood and stress response. L-Tryptophan also supports immune functions because it is the body's precursor to the kynurenines that regulate immunity. If needed, L-tryptophan converts to niacin in the body, which supports circulation, a healthy nervous system, the metabolism of food, and the production of hydrochloric acid for the digestive system. Source Naturals L-Tryptophan is extremely pure and is regularly tested to ensure the highest standards of quality.

Suggested Use

1 tablet three times daily, between meals and preferably with fruit juice. To support restful sleep, take 3 tablets before bed.

Other Ingredients

Dibasic calcium phosphate, stearic acid, modified cellulose gum, and silica .

Suitable for vegetarians and Hypoallergenic: Contains no yeast, dairy, egg, gluten, corn, soy or wheat. Contains no sugar, starch, salt, preservatives, or artificial color, flavor or fragrance.


Caution: If you are pregnant, may become pregnant, breastfeeding, or are taking medications such as SSRIs or MAOIs consult your health care professional before using this product.

Store in a cool, dry place.

Do not use if either tamper-evident seal is broken or missing. Keep out of the reach of children.

Supplement Facts
Serving Size: 3 Tablets
Servings Per Container: 40
  Amount Per Serving %DV
Calcium 52 mg 5%
Iron (naturally occurring) 570 mcg 3%
L-Tryptophan 1.5 g
†Daily Value not established.
iHerb Customer Reviews


Posted by 5490963170685634287 on Jan 21, 2017


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good with Melatonin

Posted by 5115357025179437096 on Dec 10, 2016

i take it together with Melatonin and it usually replace sleeping piills.

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All around GREAT!

Posted by Reviewer1972894 on Nov 02, 2016

This helps curb a low mood swing with 1-2 tablets. To help fall asleep 2-3 tablets, repeat if waking up again midway through the night. This has replaced my antidepressants and no side effects! So wonderful!

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Worked better than medication for me

Posted by SharonChua on Oct 29, 2016

I had been on and off Prozac and lose dose xanax for several years, and they have lost much of their effectiveness for me. L-tryptophan had an immediate effect the very first night I took it, and has continued to work for about a month now. I take 3 pills nightly on a relatively empty stomach. Very grateful for these because I had suffered from terrible sleep for several months prior. I was achy, exhausted and bad-tempered because of it. Now sleep has completely normalized and I can feel that it's deep, restorative sleep. I'm groggy in the morning but a cup of coffee takes it away immediately. I pray this continues to work, am quite amazed actually that a natural supplement has this strong an effect.

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Posted by 4652955998457969064 on Jul 16, 2016

These tablets are fantastic if you are having trouble sleeping. I recently lost my son and couldn't sleep but these made me relax and had a great sleep with no after effects, highly recommend them.

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