| 10 Now Foods L-Tryptophan PowderSupplement Rating   | 8 Life Extension L-TryptophanSupplement Rating   | 11 Life Extension Optimized Tryptophan PlusSupplement Rating   | 7 Jarrow Formulas L-Tryptophan PeptideSupplement Rating   | |
|---|---|---|---|---|
| Serving Size | 1/4 Level Teaspoons (approx. 1 g) | 1 Vegetarian Capsule | 3 Vegetarian Capsules | 2 Tablets | 
| Price/Serving | $0.34 | $0.28 18% | $0.82 141% | $0.66 94% | 
| Servings Per Container | 57 | 90 58% | 30 47% | 30 47% | 
| Tryptophan | 950 mg (Free-Form) | 500 mg | 285 mg Perluxan Hops Standardized Extract (cones) and Ursole Rosemary Standardized Extract (leaves) | 500 mg (from L-Tryptophan Peptides [PepForm]) | 
| Vitamin B3 | missing substance or information* | missing substance or information* | 66 mg (as niacinamide) | missing substance or information* | 
| Lysine | missing substance or information* | missing substance or information* | 250 mg (as L-Lysine HCl) | missing substance or information* | 
*Some information on the Now Foods L-Tryptophan Powderlabel may be missing, or it may have been written incorrectly. We work hard to keep the information accurate & up to date. Please let us know if you discover any errors.