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Ingredient file // Flavor

Thyme Extract

A little flavor, not a health treatment

Thyme extract concentrates compounds from thyme leaves and tender stems into a small botanical additive. In dog food it adds herbal flavor and could slow fat oxidation during storage. Its place on the label gives no reason to expect a health benefit for the dog.

What it is
A concentrated preparation made by drawing aromatic and other soluble compounds from thyme leaves and stems.
Made from
Thyme leaves and tender stems
Main job
Herbal flavor
Typical amount
Not published
Watch for
Do not substitute concentrated thyme oil
Not the same as
Thyme essential oil

Our read // In our catalog

In 1 of every 137 foods we track

Share of foods that list it

1%

19 of the 2,595 foods with an ingredient list on file, from 2 brands. All dry dog food.

Each square is 1% of the catalog

Where it sits on the label

Median position 37. In the top five of 0 foods, so it is usually a minor ingredient.

Top five List position, heaviest first

Above the salt

0%

Usually listed after the salt, which caps it at roughly 1% of the recipe in 100% of foods.

Price per lb

Foods with it $3.43
All foods $3.23

Median of the cheapest bag price across 14 priced foods, 6% above the catalog. The price is the food's, not the ingredient's.

Who leans on it

89%

of the foods that list it are from Health Extension. 2 brands use it in total.

What it is

How it is made

Herb processors make extracts to concentrate thyme's aroma and soluble compounds. They dry and chop the leaves and tender stems, draw compounds into a liquid, then remove the spent plant matter and much of the liquid.2

  1. 01 // Source Thyme tops Leaves and small stems are harvested and dried before extraction.
  2. 02 // Process Chopped The dried herb is broken into smaller pieces so the extraction liquid reaches more surface.
  3. 03 // Process Liquid extraction Ethanol draws soluble compounds from the herb in the methods used for the tested extracts.
  4. 04 // Process Filtered and concentrated Plant solids are filtered out, and liquid is evaporated to concentrate the tested extracts.
  5. 05 // Output Thyme extract A concentrated preparation is used as an additive rather than as ground whole herb.

What is in it

Composition, dry matter

5.17

% rosmarinic

The highest rosmarinic acid share measured in a dry laboratory extract. It describes that sample, not every thyme extract on a bag.

Rosmarinic acid 261.6-51,687 mg/kg2
Luteolin 1,554.9-4,143.4 mg/kg2
Carvacrol 220.5-5,595.4 mg/kg2

These ranges come from dry extracts made by different laboratory methods. Extraction conditions changed the concentrations sharply, so the figures do not tell you the strength or composition of the extract in a particular food.2

Why it is in the bag

What the manufacturer gets

  1. 01

    Adds herbal flavor

    Thyme preparations bring an aromatic note to food. A feed safety assessment treats thyme oil as a flavoring additive, but does not test whether dogs prefer a thyme flavored recipe.5

  2. 02

    Slows fat oxidation

    Thyme extract delayed oxidation in stored sunflower oil, while isolated thymol protected poultry feed. Neither experiment shows how much protection a particular kibble gets from its listed extract.3,4

  3. 03

    Adds little bulk

    Laboratory methods recovered 1.62 to 9.25% of the dry herb as extract. Growing and processing thyme to supply bulk protein or fiber would be inefficient.2,6

How much A typical dog food amount is not published; a separate assessment judged specified thyme essential oil safe for dogs at 100 mg/kg of complete feed.5

Our read // The claims

What the evidence supports

Strong: controlled studies in dogs agree. Some: small or mixed dog data. Thin: mechanism or lab work only. None: nothing, or the evidence points the other way.

  1. Brands say

    Thyme extract naturally preserves the kibble

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    A 29-day storage test found that 1% thyme extract slowed oxidation in sunflower oil. Isolated thymol also protected poultry feed. Neither test measured this ingredient at the amount used in a labeled dog food.3,4

  2. Owners say

    Thyme extract gets rid of intestinal worms

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    Researchers gave oral extract to 20 infected puppies for 3 days. Egg counts did not fall in 2 puppies, and there was no untreated comparison group. A small treatment trial cannot make a food ingredient a dewormer.1

  3. Brands say

    Its antioxidants protect a dog's health

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    Researchers compared 6 laboratory extraction methods and measured different phenolic concentrations and antioxidant test results. Those tests measured material in a lab, not health outcomes in dogs eating thyme extract in food.2

  4. Brands say

    A natural extract is safer than synthetic additives

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    AAFCO's natural label guidance makes no safety comparison. A feed assessment judged a specified thyme oil safe for dogs at 100 mg/kg, but that result does not cover every thyme preparation.5,7

Straight answers

What owners ask

  1. Q01

    Is it just filler?

    No

    It is a minor flavoring ingredient, not bulk material added for protein, fiber or calories. Its low place on a weight ordered ingredient list fits a concentrated additive.5,6

  2. Q02

    Does it preserve the food?

    Possibly

    Thyme extract slowed oxidation in a sunflower oil experiment. A bag does not disclose the extract's strength or amount, so the ingredient line alone cannot tell you how well that recipe's fat is protected.2,3

  3. Q03

    Can it replace a dewormer?

    No

    The puppy study used a measured oral treatment, had no untreated comparison group, and found no egg count reduction in some puppies. It says nothing about the amount in a complete food.1

Who uses it

Brands, best sellers and the company it keeps

Top brands, by foods that list it

  1. Health Extension 17
  2. Heed Foods 2

Usually listed with, share of the foods that list it

  1. Dried Beet Pulp 68%
  2. Sweet Potatoes 58%
  3. Chicken 53%
  4. Brown Rice 53%
  5. Salmon Oil 47%
  6. Flaxseed 47%
  7. Chicken Meal 47%
  8. Chicken Fat 47%
  9. Pearled Barley 47%
  10. Brewers Dried Yeast 47%
  11. Oatmeal 37%
  12. Menhaden Fish Meal 37%

Our read // On the bag

Judge the food around the thyme

When thyme extract sits among the minor ingredients, read it as flavor with possible help protecting fat during storage. Check the main protein and fat sources and the food's nutritional adequacy statement before giving the herb line weight. Do not treat it as an antioxidant supplement or a dewormer.

Sources

What we read

Checked October 1, 2026.

  1. 1 The therapeutic effectiveness of thyme extract in naturally infected puppies with ascariasis Turkish Journal of Veterinary Research, 2023 // Journal
  2. 2 Chemical Composition and Antioxidant Activity of Thyme, Hemp and Coriander Extracts: A Comparison Study of Maceration, Soxhlet, UAE and RSLDE Techniques Foods, 2020 // Journal
  3. 3 Antioxidative effect of thyme (Thymus vulgaris) in sunflower oil Acta Scientiarum Polonorum Technologia Alimentaria, 2012 // Journal
  4. 4 Thymol as natural antioxidant additive for poultry feed: oxidative stability improvement Poultry Science, 2017 // Journal
  5. 5 Safety and efficacy of a feed additive consisting of an essential oil obtained from the flowering aerial parts of Thymus vulgaris L. and/or Thymus zygis L. (thyme oil) for use in all animal species (FEFANA asbl) EFSA Journal, 2025 // Regulator
  6. 6 What’s in the Ingredients List? AAFCO, n.d. // Regulator
  7. 7 Natural AAFCO, n.d. // Regulator
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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