PlainVitamins

Best L-Tryptophan 500 mg

by Doctor's Best · capsule · 90 veggie caps

  • On the market (NIH)
  • UPC 7 53950 00161 9
  • DSLD label 25210
  • Serving 1 to 2 capsules; amounts per 1 capsule
  • 90 servings

Best L-Tryptophan 500 mg by Doctor's Best lists 4 ingredients, 4 with an amount per serving of 1 capsule, such as 20 mg of niacin, 10 mg of vitamin B6 and 500 mg of L-tryptophan. Its current label entered the NIH Dietary Supplement Label Database on September 25, 2013.

What is in Best L-Tryptophan 500 mg?

Each row as the label prints it, per serving of 1 capsule. The capsule beside an amount places it among every product in the NIH database that lists the same ingredient: the bar is the middle half of their amounts, the line in it the median, the whiskers the 10th and 90th percentiles; the green tick is the FDA Daily Value and the red dashed tick the adult upper limit (IOM).

Best L-Tryptophan 500 mg: Supplement Facts rows against the market (DSLD label 25210, January 2026 release)
IngredientAmount% DVAmong products listing it
Niacinas NiacinamideNiacin (Form: as Niacinamide)20 mg100%Niacin in Best L-Tryptophan 500 mg against 12,413 products20 mg per serving; the middle half of products list 13.2 mg to 48 mg, the median 20 mg.DV 16 mgUL 35 mg20 mg

46% of 12,413 products listing niacin give more (median 20 mg).

Vitamin B610 mg500%Vitamin B6 in Best L-Tryptophan 500 mg against 15,277 products10 mg per serving; the middle half of products list 2 mg to 20 mg, the median 6 mg.DV 1.7 mgUL 100 mg10 mg

Higher than 55% of 15,277 products listing vitamin B6 (median 6 mg).

from 17.6 mg pyridoxal 5-phosphate17.6 mg
L-TryptophanAjinomoto L-Tryptophan500 mgTryptophan in Best L-Tryptophan 500 mg against 605 products500 mg per serving; the middle half of products list 55 mg to 471 mg, the median 123 mg.500 mg

Higher than 76% of 605 products listing tryptophan (median 123 mg).

Source: NIH ODS Dietary Supplement Label Database, label 25210 (entered September 25, 2013), version 9.4.0. See the label on DSLD. Amounts are what the maker printed; DSLD does not test products. Daily Values: the FDA's Daily Value page.

Is that a lot?

Every amount on this label with a position sits within the middle 80% of the products that list the same ingredient.

The NIH database records one serving a day from the label's directions; its % Daily Values are for adults and children 4 or more years of age. The directions as printed are further down this page.

The Tolerable Upper Intake Level is the most of a nutrient per day, from food, water and supplements together, that is likely to pose no risk for almost all adults (Institute of Medicine, 2011). It does not apply under medical supervision. This page compares labels; it is not medical advice.

Sources: amounts from the DSLD label; Daily Values from 21 CFR 101.9(c)(8)(iv); adult upper limits from the Institute of Medicine's DRI summary tables (2011). How positions are computed.

Which products have the closest formulas?

The products whose ingredient lists overlap most with Best L-Tryptophan 500 mg's, rare ingredients counting for more.

Source: ingredient lists of every product's current label in DSLD (version 9.4.0); similarity weights each shared ingredient by how rare it is.

What does the label say about taking it?

Quoted from the label as DSLD transcribed it: the maker's words, including any claim about what the product does, which the FDA has not evaluated and PlainVitamins does not endorse.

Directions
Suggested Adult Use: Take 1 or 2 capsules daily. For optimum absorption, take separately from protein-containing foods and dietary supplements containing protein or amino acids.

Source: label statements in DSLD label 25210.

What else is on the label?

Other ingredients: Modified Cellulose, Cellulose, Magnesium Stearate, Silicon Dioxide.

Seals and symbols as the label prints them (the maker's; a certifier's own list confirms a seal): AJIPURE(TM) AMINO ACIDS.

How many labels does Best L-Tryptophan 500 mg have?

4 labels are on file under this name since October 26, 2011: other sizes, label designs and reformulations. The current one leads this page.

  1. Label 25210 (current) Entered September 25, 2013 · on the market · 90 veggie caps · UPC 7 53950 00161 9
  2. Label 25209 Entered September 25, 2013 · on the market · 10 veggie caps · UPC 7 53950 00202 9
  3. Label 24588 Entered August 23, 2013 · off the market May 2, 2016 · 90 veggie caps · UPC 7 53950 00126 8
  4. Label 1258 Entered October 26, 2011 · off the market April 1, 2013 · 90 veggie caps · UPC 7 53950 00126 8

Source: DSLD label entry and market events, version 9.4.0 (labels entered through September 25, 2025).

Who makes it?

The label names Doctor's Best, Inc. (distributor), San Clemente, CA. All Doctor's Best products.

Where next?