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Ingredient file

L-Tryptophan

An added form of the essential amino acid tryptophan.

Our read // In our catalog

In 1 of every 26 foods we track

Share of foods that list it

4%

122 of the 3,204 foods with an ingredient list on file, from 19 brands. 99 dry dog food, 12 wet dog food, 7 frozen dog food.

Each square is 1% of the catalog

Where it sits on the label

Median position 26.5. In the top five of 0 foods, so it is usually a minor ingredient.

Top five List position, heaviest first

Above the salt

6%

Usually listed after the salt, which caps it at roughly 1% of the recipe in 94% of foods.

Price per lb

Foods with it $3.00
All foods $3.25

Median of the cheapest bag price across 91 priced foods, 8% below the catalog. The price is the food's, not the ingredient's.

Who leans on it

17%

of the foods that list it are from Fromm. 19 brands use it in total.

What it is

Why it turns up in dog food

  • The precursor the body uses to make serotonin, which is why it appears in recipes aimed at calm behavior.

Who uses it

Brands, best sellers and the company it keeps

Top brands, by foods that list it

  1. Fromm 21 / 67
  2. Hill's 20 / 116
  3. Blue 20 / 186
  4. Royal Canin 18 / 160
  5. Pedigree 15 / 42
  6. NutriSource 6 / 91
  7. Merrick 3 / 107
  8. Purina 3 / 185
  9. Go! Solutions 2 / 46
  10. Now Fresh 2 / 35

Foods that list it / all the brand's recipes we track.

Plus 9 more brands.

Amazon best sellers that list it

  1. #12 Pedigree Adult Grilled Steak & Vegetable Flavor Dry Dog Food
  2. #22 Cesar Filet Mignon Flavor & Spring Vegetables Garnish Dry Dog Food
  3. #41 Pedigree Small Dog Grilled Steak and Vegetable Flavor Dry Dog Food
  4. #73 Pedigree Puppy Chicken & Vegetable Flavor Dry Dog Food
  5. #87 Iams Adult Healthy Weight Dry Dog Food

Rank on Amazon's dog food best seller list, checked October 2026.

Usually listed with, share of the foods that list it

  1. Natural Flavor 48%
  2. Brown Rice 39%
  3. Chicken Fat 39%
  4. Chicken 39%
  5. Dried Plain Beet Pulp 30%
  6. Chicken Meal 28%
  7. Brewers Rice 27%
  8. Chicken By-Product Meal 25%
  9. Corn Gluten Meal 22%
  10. Mixed Tocopherols 20%
  11. Peas 19%
  12. Oatmeal 19%

On the shelf

Foods that list L-Tryptophan

122 foods in our catalog list it. These 60 list it highest on the label.

Merrick Fresh Selects Turkey & Brown Rice Fresh Frozen Dog FoodMerrickMerrick Fresh Selects Turkey & Brown Rice Fresh Frozen Dog FoodFrozen // No. 8 on the labelMerrick Fresh Selects Chicken & Brown Rice Fresh Frozen Dog FoodMerrickMerrick Fresh Selects Chicken & Brown Rice Fresh Frozen Dog FoodFrozen // No. 8 on the labelGo! Solutions Tranquility Minced Chicken with Gravy Grain-Free Dog Food TopperGo! SolutionsGo! Solutions Tranquility Minced Chicken with Gravy Grain-Free Dog Food TopperTopper // No. 14 on the labelInstinct Raw Boost RawBoost+ Mixers Tranquility Recipe Dog Food TopperInstinctInstinct Raw Boost RawBoost+ Mixers Tranquility Recipe Dog Food TopperTopper // No. 14 on the labelNatural Balance Zen Life Dry Dog FoodNatural BalanceNatural Balance Zen Life Dry Dog FoodDry // No. 15 on the labelHill’s Prescription Diet d/d Salmon Skin Care Wet Dog FoodHill'sHill’s Prescription Diet d/d Salmon Skin Care Wet Dog FoodWet // No. 16 on the labelGo! Solutions Tranquility Chicken, Salmon + Duck Stew Grain-Free Dog Food TopperGo! SolutionsGo! Solutions Tranquility Chicken, Salmon + Duck Stew Grain-Free Dog Food TopperTopper // No. 16 on the labelNulo FreeStyle Limited+ Lamb Recipe Grain-Free Dry Dog FoodNuloNulo FreeStyle Limited+ Lamb Recipe Grain-Free Dry Dog FoodDry // No. 16 on the labelPedigree Adult, Roasted Lamb & Vegetable Dry Dog FoodPedigreePedigree Adult, Roasted Lamb & Vegetable Dry Dog FoodDry // No. 18 on the labelPurina Alpo Come & Get It! Cookout Classics Dry Dog FoodPurinaPurina Alpo Come & Get It! Cookout Classics Dry Dog FoodDry // No. 18 on the labelWysong Vegan Dry Dog FoodWysongWysong Vegan Dry Dog FoodDry // No. 19 on the labelPedigree Small Dog Roasted Chicken, Rice & Vegetable Flavor Dry Dog FoodPedigreePedigree Small Dog Roasted Chicken, Rice & Vegetable Flavor Dry Dog FoodDry // No. 19 on the label
Show 48 more
Merrick Fresh Selects Beef & Brown Rice Fresh Frozen Dog FoodMerrickMerrick Fresh Selects Beef & Brown Rice Fresh Frozen Dog FoodFrozen // No. 9 on the labelPedigree Small Dog Grilled Steak and Vegetable Flavor Dry Dog FoodPedigreePedigree Small Dog Grilled Steak and Vegetable Flavor Dry Dog FoodDry // No. 20 on the labelPedigree Puppy Chicken & Vegetable Flavor Dry Dog FoodPedigreePedigree Puppy Chicken & Vegetable Flavor Dry Dog FoodDry // No. 20 on the labelHill’s Prescription Diet i/d Puppy Turkey Digestive Care Wet Dog FoodHill'sHill’s Prescription Diet i/d Puppy Turkey Digestive Care Wet Dog FoodWet // No. 20 on the labelNow Fresh Good Gravy Beef Minced Grain-Free Wet Dog FoodNow FreshNow Fresh Good Gravy Beef Minced Grain-Free Wet Dog FoodWet // No. 20 on the labelPedigree Adult, Roasted Chicken & Vegetable Dry Dog FoodPedigreePedigree Adult, Roasted Chicken & Vegetable Dry Dog FoodDry // No. 20 on the labelRoyal Canin Veterinary Ultamino Dry Dog FoodRoyal CaninRoyal Canin Veterinary Ultamino Dry Dog FoodDry // No. 20 on the labelPedigree Big Dogs Roasted Chicken, Rice & Vegetable Dry Dog FoodPedigreePedigree Big Dogs Roasted Chicken, Rice & Vegetable Dry Dog FoodDry // No. 20 on the labelPedigree Adult Roasted Chicken, Rice & Vegetable Flavor Dry Dog FoodPedigreePedigree Adult Roasted Chicken, Rice & Vegetable Flavor Dry Dog FoodDry // No. 20 on the labelNow Fresh Good Gravy Beef & Lamb Grain-Free Wet Dog FoodNow FreshNow Fresh Good Gravy Beef & Lamb Grain-Free Wet Dog FoodWet // No. 21 on the labelBlue True Solutions Weight Control Wet Dog FoodBlueBlue True Solutions Weight Control Wet Dog FoodWet // No. 21 on the labelPedigree with MarroBites Adult, Grilled Steak and Vegetable Dry Dog FoodPedigreePedigree with MarroBites Adult, Grilled Steak and Vegetable Dry Dog FoodDry // No. 21 on the labelHill’s Prescription Diet j/d Joint Care Small Bites Chicken Flavor Dry Dog FoodHill'sHill’s Prescription Diet j/d Joint Care Small Bites Chicken Flavor Dry Dog FoodDry // No. 21 on the labelPurina Dog Chow Complete Adult with Real Beef Dry Dog FoodPurinaPurina Dog Chow Complete Adult with Real Beef Dry Dog FoodDry // No. 21 on the labelPedigree Puppy Grilled Steak & Vegetable Flavor Dry Dog FoodPedigreePedigree Puppy Grilled Steak & Vegetable Flavor Dry Dog FoodDry // No. 21 on the labelPedigree Healthy Weight Roasted Chicken, & Vegetable Flavor Dry Dog FoodPedigreePedigree Healthy Weight Roasted Chicken, & Vegetable Flavor Dry Dog FoodDry // No. 21 on the labelPedigree Adult Grilled Steak & Vegetable Flavor Dry Dog FoodPedigreePedigree Adult Grilled Steak & Vegetable Flavor Dry Dog FoodDry // No. 22 on the labelHill’s Prescription Diet z/d Hydrolyzed Chicken Flavor Wet Dog FoodHill'sHill’s Prescription Diet z/d Hydrolyzed Chicken Flavor Wet Dog FoodWet // No. 22 on the labelHill’s Prescription Diet z/d Skin/Food Sensitivities Small Bites Original Flavor Dry Dog FoodHill'sHill’s Prescription Diet z/d Skin/Food Sensitivities Small Bites Original Flavor Dry Dog FoodDry // No. 22 on the labelBlue Natural Veterinary Diet HF Hydrolyzed for Food Intolerance Grain-Free Dry Dog FoodBlueBlue Natural Veterinary Diet HF Hydrolyzed for Food Intolerance Grain-Free Dry Dog FoodDry // No. 22 on the labelDave’s Pet Food Restricted Diet Low Phosphorus Tuna Paté Dog Food TopperDave's Pet FoodDave’s Pet Food Restricted Diet Low Phosphorus Tuna Paté Dog Food TopperTopper // No. 23 on the labelBlue True Solutions Small Breed Care Chicken & Oatmeal Recipe for Small Breed Adult Dogs Dry Dog FoodBlueBlue True Solutions Small Breed Care Chicken & Oatmeal Recipe for Small Breed Adult Dogs Dry Dog FoodDry // No. 23 on the labelHill’s Science Diet Adult 7+ Small & Mini Chicken & Barley Entrée Wet Dog FoodHill'sHill’s Science Diet Adult 7+ Small & Mini Chicken & Barley Entrée Wet Dog FoodWet // No. 23 on the labelRoyal Canin Veterinary Urinary SO Dry Dog FoodRoyal CaninRoyal Canin Veterinary Urinary SO Dry Dog FoodDry // No. 23 on the labelRoyal Canin Veterinary Renal Support S Dry Dog FoodRoyal CaninRoyal Canin Veterinary Renal Support S Dry Dog FoodDry // No. 23 on the labelHill’s Prescription Diet w/d Multi-Benefit Chicken Flavor Dry Dog FoodHill'sHill’s Prescription Diet w/d Multi-Benefit Chicken Flavor Dry Dog FoodDry // No. 23 on the labelRoyal Canin Large Aging 8+ Dry Dog FoodRoyal CaninRoyal Canin Large Aging 8+ Dry Dog FoodDry // No. 23 on the labelBlue Natural Veterinary Diet GI Low Fat Wet Dog FoodBlueBlue Natural Veterinary Diet GI Low Fat Wet Dog FoodWet // No. 24 on the labelRoyal Canin Veterinary Renal Support A Dry Dog FoodRoyal CaninRoyal Canin Veterinary Renal Support A Dry Dog FoodDry // No. 24 on the labelRoyal Canin Veterinary Multifunction Renal Support + Hydrolyzed Protein Dry Dog FoodRoyal CaninRoyal Canin Veterinary Multifunction Renal Support + Hydrolyzed Protein Dry Dog FoodDry // No. 24 on the labelRoyal Canin Medium Aging 10+ Dry Dog FoodRoyal CaninRoyal Canin Medium Aging 10+ Dry Dog FoodDry // No. 24 on the labelRoyal Canin Large Comfort Care Dry Dog FoodRoyal CaninRoyal Canin Large Comfort Care Dry Dog FoodDry // No. 24 on the labelPedigree Tender Bites Chicken & Steak Flavor Dry Dog FoodPedigreePedigree Tender Bites Chicken & Steak Flavor Dry Dog FoodDry // No. 24 on the labelPedigree High Protein Beef and Lamb Flavor Dry Dog FoodPedigreePedigree High Protein Beef and Lamb Flavor Dry Dog FoodDry // No. 24 on the labelNatural Balance Original Ultra Whole Body Health Chicken, Chicken Meal & Duck Meal Dry Dog FoodNatural BalanceNatural Balance Original Ultra Whole Body Health Chicken, Chicken Meal & Duck Meal Dry Dog FoodDry // No. 24 on the labelFromm Classic Adult Whitefish & Rice Recipe Dry Dog FoodFrommFromm Classic Adult Whitefish & Rice Recipe Dry Dog FoodDry // No. 25 on the labelRoyal Canin Veterinary Renal Support F Dry Dog FoodRoyal CaninRoyal Canin Veterinary Renal Support F Dry Dog FoodDry // No. 25 on the labelRoyal Canin Veterinary Urinary SO Aging 7+ Dry Dog FoodRoyal CaninRoyal Canin Veterinary Urinary SO Aging 7+ Dry Dog FoodDry // No. 25 on the labelNutriSource Grain-Free Large Breed Lamb Meal & Peas Recipe Dry Dog FoodNutriSourceNutriSource Grain-Free Large Breed Lamb Meal & Peas Recipe Dry Dog FoodDry // No. 25 on the labelPedigree High Protein Chicken & Turkey Flavor Dry Dog FoodPedigreePedigree High Protein Chicken & Turkey Flavor Dry Dog FoodDry // No. 25 on the labelFromm Classic Adult Dry Dog FoodFrommFromm Classic Adult Dry Dog FoodDry // No. 25 on the labelBlue Natural Veterinary Diet NP Novel Protein Alligator Grain-Free Dry Dog FoodBlueBlue Natural Veterinary Diet NP Novel Protein Alligator Grain-Free Dry Dog FoodDry // No. 25 on the labelHill’s Science Diet Puppy Sensitive Stomach & Skin Salmon & Brown Rice Recipe Dry Dog FoodHill'sHill’s Science Diet Puppy Sensitive Stomach & Skin Salmon & Brown Rice Recipe Dry Dog FoodDry // No. 26 on the labelRoyal Canin Veterinary Calm Dry Dog FoodRoyal CaninRoyal Canin Veterinary Calm Dry Dog FoodDry // No. 26 on the labelHill’s Prescription Diet i/d Digestive Care Small Bites Chicken Flavor Dry Dog FoodHill'sHill’s Prescription Diet i/d Digestive Care Small Bites Chicken Flavor Dry Dog FoodDry // No. 26 on the labelRoyal Canin Medium Comfort Care Dry Dog FoodRoyal CaninRoyal Canin Medium Comfort Care Dry Dog FoodDry // No. 26 on the labelIams Adult Healthy Weight Large Breed Dry Dog FoodIamsIams Adult Healthy Weight Large Breed Dry Dog FoodDry // No. 26 on the labelFromm Classic Puppy Dry Dog FoodFrommFromm Classic Puppy Dry Dog FoodDry // No. 26 on the label
An ingredient on its own tells you very little. What matters is how much of it there is and where it sits in the list. That is why we weigh the top five rather than reacting to any single name further down. Back to the wiki

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