Amino acids
L-tryptophan
An essential amino acid from milk, poultry and oats. Your body uses it to make serotonin and melatonin, which play a part in mood and sleep.
35 products from US online stores, sorted by what 500 mg of tryptophan costs – not by the price per pack.
3.2¢Lowest cost
per 500 mg tryptophan
- Prices checked Nov 1, 2026, US
- No paid placements
What does 500 mg mean?
- tryptophan per serving in most of the products we checked
- 500–1,000 mgtryptophan per serving in most of the products we checked
- 500 mg is about one serving: half of the 35 products we checked have up to 500 mg per serving, the other half more.
- There’s no official daily amount for tryptophan.
We compare by 500 mg only so products line up – it’s not a recommendation. Not medical advice.
Where products miss quality points
How the 35 products score
- Very good 90+: 0
- Good 75+: 34
- Fair 60+: 0
- Low under 60: 1
1 product contains titanium dioxide – a food authority has banned, restricted or flagged it as a possible health risk. Its score is cut in half, so it’s always in the red range. The product says why.
- have no seal from an independent testing program
- 100%have no seal from an independent testing program10 of 30 testing points for GMP, 15 for the 4 whose label says “third-party tested”
The full 30 testing points need an independent test. Every supplement sold in the US is made under the FDA’s GMP rules – the maker checks its own products, which gives 10 points. A seal from a testing program like NSF, USP or Informed Choice means a lab outside the company checks that what’s inside matches the label. Most brands don’t take part. That doesn’t make a product bad – without a seal, a clean product still gets up to 80.
We find seals on the label and in NSF’s public lists. USP and Informed Choice don’t let us search their lists automatically, so a seal that’s only in their lists can be missing. How the score works
Pack size
Compare packs of a similar size.
All sizes in one list can affect the results – big packs usually cost less per 500 mg. Pick a size above to compare packs that are alike.
35 products · cheapest per 500 mg tryptophan first
- Rank 1
BulkSupplements
L-Tryptophan Powder
Powder
80Good qualityCountry not stated3.2¢per 500 mg
Lowest
- Pack
- $31.971,000 servings
- Tryptophan per serving
- 500 mg
- Pack lasts
- 1,000 daysif you take 500 mg a day
bulksupplements.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 2
BulkSupplements
L-Tryptophan Powder
Powder
80Good qualityCountry not stated4.6¢per 500 mg
44% more
- Pack
- $22.97500 servings
- Tryptophan per serving
- 500 mg
- Pack lasts
- 500 daysif you take 500 mg a day
bulksupplements.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 3
Vitamatic
L-Tryptophan 1000mg Supplement
Tablets
80Good qualityCountry not stated6.2¢per 500 mg
95% more
- Pack
- $14.99120 tablets
- Tryptophan per serving
- 1,000 mgin 1 tablet
- Pack lasts
- 120 daysif you take 1 tablet (1,000 mg) a day
vitamaticusa.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 4
Vitamatic
L-Tryptophan, 1,000 mg
Tablets
80Good qualityCountry not stated6.7¢per 500 mg
108% more
- Pack
- $15.99120 tablets
- Tryptophan per serving
- 1,000 mgin 1 tablet
- Pack lasts
- 120 daysif you take 1 tablet (1,000 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 5
Amazing Nutrition
Amazing Formulas L-Tryptophan 1000 Mg
Tablets
85Good qualityMade in USA7.6¢per 500 mg
138% more
- Pack
- $36.49240 tablets
- Tryptophan per serving
- 1,000 mgin 1 tablet
- Pack lasts
- 240 daysif you take 1 tablet (1,000 mg) a day
amazingnutrition.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 6
Amazing Nutrition
Amazing Formulas L-Tryptophan - 1000 Mg
Tablets
80Good qualityMade in USA8.3¢per 500 mg
160% more
- Pack
- $9.9960 tablets
- Tryptophan per serving
- 1,000 mgin 1 tablet
- Pack lasts
- 60 daysif you take 1 tablet (1,000 mg) a day
amazingnutrition.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 7
Amazing Nutrition
Nutri Essentials L-Tryptophan 500 Mg Amino Acid Supplement
Capsules
85Good qualityMade in USA8.3¢per 500 mg
160% more
- Pack
- $9.99120 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 120 daysif you take 1 capsule (500 mg) a day
amazingnutrition.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 8
Best Naturals
L-Tryptophan 500 mg
Capsules
80Good qualityMade in USA8.3¢per 500 mg
160% more
- Pack
- $9.99120 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 120 daysif you take 1 capsule (500 mg) a day
shopbestnaturals.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 9
Amazing Nutrition
Amazing Formulas L-Tryptophan - 1000 Mg
Tablets
80Good qualityMade in USA8.3¢per 500 mg
161% more
- Pack
- $19.99120 tablets
- Tryptophan per serving
- 1,000 mgin 1 tablet
- Pack lasts
- 120 daysif you take 1 tablet (1,000 mg) a day
amazingnutrition.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 10
Amazing Nutrition
Amazing Formulas L-Tryptophan - 500 Mg
Capsules
80Good qualityCountry not stated8.3¢per 500 mg
161% more
- Pack
- $19.99240 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 240 daysif you take 1 capsule (500 mg) a day
amazingnutrition.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 11
Best Naturals
L-Tryptophan 1000 mg
Tablets
80Good qualityMade in USA9.2¢per 500 mg
186% more
- Pack
- $10.9960 tablets
- Tryptophan per serving
- 1,000 mgin 1 tablet
- Pack lasts
- 60 daysif you take 1 tablet (1,000 mg) a day
shopbestnaturals.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 12
Amazing Nutrition
L-Tryptophan, 1,000 mg
Tablets
80Good qualityMade in USA9.2¢per 500 mg
187% more
- Pack
- $21.99120 tablets
- Tryptophan per serving
- 1,000 mgin 1 tablet
- Pack lasts
- 120 daysif you take 1 tablet (1,000 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 13
BulkSupplements
L-Tryptophan Capsules
Capsules
80Good qualityCountry not stated9.6¢per 500 mg
199% more
- Pack
- $22.96240 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 240 daysif you take 1 capsule (500 mg) a day
bulksupplements.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 14
BulkSupplements
L-Tryptophan Powder
Powder
80Good qualityCountry not stated$0.10per 500 mg
228% more
- Pack
- $20.97200 servings
- Tryptophan per serving
- 500 mg
- Pack lasts
- 200 daysif you take 500 mg a day
bulksupplements.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 15
Amazing Nutrition
L-Tryptophan, 1,000 mg
Tablets
80Good qualityMade in USA$0.11per 500 mg
238% more
- Pack
- $12.9860 tablets
- Tryptophan per serving
- 1,000 mgin 1 tablet
- Pack lasts
- 60 daysif you take 1 tablet (1,000 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 16
Amazing Nutrition
Amazing Formulas L-Tryptophan - 500 Mg
Capsules
80Good qualityMade in USA$0.12per 500 mg
290% more
- Pack
- $14.95120 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 120 daysif you take 1 capsule (500 mg) a day
amazingnutrition.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 17
Nutricost
L-Tryptophan, 500 mg
Capsules
85Good qualityMade in USA$0.13per 500 mg
316% more
- Pack
- $15.95120 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 120 daysif you take 1 capsule (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 18
NOW Foods
L-Tryptophan, 1,000 mg
Tablets
80Good qualityMade in USA$0.14per 500 mg
343% more
- Pack
- $17.0060 tablets
- Tryptophan per serving
- 1,000 mgin 1 tablet
- Pack lasts
- 60 daysif you take 1 tablet (1,000 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 19
Nutricost
L-Tryptophan Capsules
Capsules
85Good qualityMade in USA$0.15per 500 mg
368% more
- Pack
- $17.97120 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 120 daysif you take 1 capsule (500 mg) a day
nutricost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 20
Amazing Nutrition
Amazing Formulas L-Tryptophan - 500 Mg
Capsules
80Good qualityMade in USA$0.17per 500 mg
420% more
- Pack
- $9.9860 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 60 daysif you take 1 capsule (500 mg) a day
amazingnutrition.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 21
BulkSupplements
L-Tryptophan Powder
Powder
80Good qualityCountry not stated$0.20per 500 mg
525% more
- Pack
- $19.97100 servings
- Tryptophan per serving
- 500 mg
- Pack lasts
- 100 daysif you take 500 mg a day
bulksupplements.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 22
NOW Foods
L-Tryptophan Powder
Powder
80Good qualityCountry not stated$0.20per 500 mg
536% more
- Pack
- $22.0357 g (2 oz)57 servings
- Tryptophan per serving
- 950 mgin 1 g
- Pack lasts
- 108 daysif you take 500 mg a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 23
Doctor's Best
L-Tryptophan, 500 mg
Capsules
80Good qualityCountry not stated$0.22per 500 mg
595% more
- Pack
- $19.9990 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 90 daysif you take 1 capsule (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 24
Doctor's Best
L-Tryptophan 500 mg
Capsules
80Good qualityCountry not stated$0.22per 500 mg
595% more
- Pack
- $19.9990 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 90 daysif you take 1 capsule (500 mg) a day
drbvitamins.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 25
Swanson Vitamins
L-Tryptophan, 500 mg
Capsules
80Good qualityCountry not stated$0.23per 500 mg
614% more
- Pack
- $13.6960 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 60 daysif you take 1 capsule (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 26
Swanson Vitamins
L-Tryptophan
Capsules
80Good qualityCountry not stated$0.23per 500 mg
614% more
- Pack
- $13.6960 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 60 daysif you take 1 capsule (500 mg) a day
swansonvitamins.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 27
Life Extension
L-Tryptophan, 500 mg
Capsules
80Good qualityCountry not stated$0.28per 500 mg
760% more
- Pack
- $24.7590 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 90 daysif you take 1 capsule (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 28
The Vitamin Shoppe
L-Tryptophan, 1,000 mg
Tablets
30Low qualityCountry not stated$0.29per 500 mg
812% more
- Pack
- $34.9960 tablets
- Tryptophan per serving
- 1,000 mgin 1 tablet
- Pack lasts
- 60 daysif you take 1 tablet (1,000 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 29
Swanson Vitamins
L-Tryptophan from TryptoPure
Capsules
80Good qualityCountry not stated$0.32per 500 mg
914% more
- Pack
- $29.1990 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 90 daysif you take 1 capsule (500 mg) a day
swansonvitamins.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 30
Swanson Vitamins
L-Tryptophan, 500 mg
Capsules
80Good qualityCountry not stated$0.34per 500 mg
965% more
- Pack
- $30.6590 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 90 daysif you take 1 capsule (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 31
Protocol for Life Balance
L-Tryptophan, 1,000 mg
Tablets
80Good qualityCountry not stated$0.34per 500 mg
967% more
- Pack
- $40.9560 tablets
- Tryptophan per serving
- 1,000 mgin 1 tablet
- Pack lasts
- 60 daysif you take 1 tablet (1,000 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 32
Bluebonnet Nutrition
L-Tryptophan, 500 mg
Capsules
80Good qualityMade in USA$0.41per 500 mg
1,191% more
- Pack
- $24.7660 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 60 daysif you take 1 capsule (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 33
Natural Balance
L-Tryptophan
Capsules
80Good qualityCountry not stated$0.49per 500 mg
1,448% more
- Pack
- $29.6960 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 60 daysif you take 1 capsule (500 mg) a day
vitacost.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 34
Bluebonnet Nutrition
L-Tryptophan 500 mg
Capsules
80Good qualityMade in USA$0.52per 500 mg
1,513% more
- Pack
- $30.9560 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 60 daysif you take 1 capsule (500 mg) a day
bluebonnetnutrition.com (opens in a new tab)Checked Nov 1, 2026 · Label
- Rank 35
Bluebonnet Nutrition
L-Tryptophan 500 mg
Capsules
80Good qualityMade in USA$0.60per 500 mg
1,772% more
- Pack
- $17.9530 capsules
- Tryptophan per serving
- 500 mgin 1 capsule
- Pack lasts
- 30 daysif you take 1 capsule (500 mg) a day
bluebonnetnutrition.com (opens in a new tab)Checked Nov 1, 2026 · Label
Good to know
- Fact
- 1,772%more per 500 mg for the most expensive product than for the cheapest.
- Fact
- 160%more per 500 mg for the cheapest capsules than for the cheapest powder.
How we checked: one-time price for each size in the store’s US online shop, before sales tax and shipping, without subscriptions or coupons. Prices change often, so check the store before you buy. More on how we check
The amount we compare by only makes products comparable – it is not a dosage recommendation. Not medical advice.
How we calculate
Cost per dose = price ÷ (servings × amount per serving) × comparison amount. Example: $119.99 for 74 servings with 24 g of protein each is 1,776 g of protein. $119.99 ÷ 1,776 g × 30 g = $2.03 per 30 g of protein.
Found a mistake or a product we should add? Email us