Why Prescribed for Life? Whether you're an individual looking to supplement your home nutritional regimen, or a large-scale manufacturer, you can always call on us to find a solution. We carry over 750 products in sizes ranging from half an ounce to metric tons. Benefit from our decades of experience in the nutritional supplement industry. We bring a personal touch to business, and we are here to support you. Herbs & Extracts Sports Nutrition Functional Foods Sweeteners Household & Industrial Cleaning Products Tryptophan (L) Essential Free Form Amino Acid Powder Prescribed for Life Tryptophan (L) is an essential amino acid. FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Non GMO Gluten Free Vegan Kosher Ashwagandha Melatonin Passion Flower St. John’s Wort Tryptophan Valerian Buying Options Add to Cart Add to Cart Add to Cart Add to Cart Add to Cart Customer Reviews — 3.7 out of 5 stars 14 5.0 out of 5 stars 1 — 5.0 out of 5 stars 2 5.0 out of 5 stars 3 Price — no data $33.99$33.99 $46.99$46.99 $20.99$20.99 $19.99$19.99 $21.99$21.99 Non GMO ✓ ✓ ✓ ✓ ✓ ✓ Gluten Free ✓ ✓ ✓ ✓ ✓ ✓ Vegan ✓ ✓ ✓ ✓ ✓ ✓ Kosher ✓ ✓ ✓ ✓ ✓ ✓