What is it used for?
Source of antioxidants/Provides antioxidants [Source note 2].
Source of antioxidants/Provides antioxidants that help fight/protect (cell) against/reduce (the oxidative effect of/the oxidative damage caused by/cell damage caused by) free radicals [Source note 3].
Source of protein (for the maintenance of good health) [Source note 4].
Source of protein which helps build and repair body tissues [Source note 5].
Source of (an) (non-essential) amino acid(s) involved in muscle protein synthesis [Source note 6].
Source of (an) (essential) amino acid(s) involved in muscle protein synthesis [Source note 7].
Source of (an) essential amino acid(s) for the maintenance of good health [Source note 8].
Note: The above uses can be combined on the product label (e.g., Source of an essential amino acid involved in muscle protein synthesis and for the maintenance of good health).
Who does this guide cover?
Adults 18 years and older
How is it taken?
Oral
Which forms are covered?
this reference excludes foods or food-like dosage forms as indicated in the Compendium of references Guidance Document.
Quantities
Antioxidants
Methods of preparation: Powdered; Defatted, ground
Not to exceed 8 grams of soy flour and/or defatted soy flour, per day [Source note 9].
Source of Protein
Method of preparation: Defatted, ground
5.5 - 8 grams of defatted soy flour, per day [Source note 10].
Method of preparation: Powdered
7.5 - 8 grams of soy flour, per day [Source note 11].
Note: If soy flour and defatted soy flour are combined, 7.5 grams should be used as the minimum total daily dose and 8 grams as the maximum total daily dose.
Source of (essential) amino acid(s) involved in muscle protein synthesis/for the maintenance of good health
Method of preparation: Defatted, ground
5.5 - 8 grams of defatted soy flour, per day [Source note 12].
Method of preparation: Powdered
7.5 - 8 grams of soy flour, per day [Source note 13].
Note: If soy flour and defatted soy flour are combined, 7.5 grams should be used as the minimum total daily dose and 8 grams as the maximum total daily dose.
OR
Method of preparation: Powdered standardized
| Essential amino acids | Minimum dose of amino acid (milligrams/day)¹ | Maximum dose of Soy flour and/or Defatted soy flour (grams/day)² |
|---|---|---|
| Histidine | 49 mg | 8 g |
| Isoleucine | 66.5 mg | 8 g |
| Leucine | 147 mg | 8 g |
| Lysine | 133 mg | 8 g |
| Methionine | 66.5 mg | 8 g |
| Phenylalanine | 115.5 mg | 8 g |
| Threonine | 70 mg | 8 g |
| Tryptophan | 17.5 mg | 8 g |
| Valine | 84 mg | 8 g |
¹1Minimum doses have been calculated as 5% of each specific amino acid Recommended Dietary Allowance with a reference weight of 70 kg [Source note 14]. ²Maximum dose [Source note 15].
Source of (non-essential) amino acids involved in muscle protein synthesis
Method of preparation: Defatted, ground
5.5 - 8 grams of defatted soy flour, per day [Source note 16].
Method of preparation: Powdered
7.5 - 8 grams of soy flour, per day [Source note 17].
Note: If soy flour and defatted soy flour are combined, 7.5 grams should be used as the minimum total daily dose and 8 grams as the maximum total daily dose.
OR
Method of preparation: Powdered standardized
| Non-Essential amino acids | Minimum dose of amino acid (milligrams/day)¹ | Maximum dose of Soy flour and/or Defatted soy flour (grams/day)² |
|---|---|---|
| Alanine | 181.5 mg | 8 g |
| Arginine | 208.5 mg | 8 g |
| Aspartic acid | 325 mg | 8 g |
| Glutamic acid | 750 mg | 8 g |
| Glycine | 160 mg | 8 g |
| Proline | 259.5 mg | 8 g |
| Serine | 175.5 mg | 8 g |
| Tyrosine | 139 mg | 8 g |
¹Minimum doses have been calculated as 5% of each specific amino acid Mean Intake with a reference weight of 70 kg [Source note 18]. ²Maximum dose [Source note 19].
How is it used?
The reference does not require an additional label statement in this section. This does not establish an absence of risk.
How long is it used?
The reference does not require an additional label statement in this section. This does not establish an absence of risk.
Warnings and precautions
The reference does not require an additional label statement in this section. This does not establish an absence of risk.
When should it be avoided?
The reference does not require an additional label statement in this section. This does not establish an absence of risk.
Possible side effects
The reference does not require an additional label statement in this section. This does not establish an absence of risk.
Storage
Must be established in accordance with the requirements described in the applicable product regulations.
Preparation details
Ingredient identity, preparation requirements, and other details that define the scope of this guide.
Ingredients and preparations
| Proper name(s) | Common name(s) | Source information / Source material(s) | Source information / Part(s) | Source information / Preparation(s) |
|---|---|---|---|---|
| Glycine max |
| Glycine max | Seed | Dry |
| Glycine max |
| Glycine max | Seed | Dry |
References: Proper name: USDA 2025; Common names: USDA 2025; Tomar and Shiao 2008; Source information: USDA 2025; Tomar and Shiao 2008.
¹Defatted flour refers to preparations where the oil has been removed.
Other ingredients
Must be chosen from the current source ingredient database and must meet the limitations outlined in the database.
Preparation and quality requirements
The finished product specifications must be established in accordance with the requirements described in the source authority source’s product quality guidance.
The active ingredient must comply with the requirements outlined in the source ingredient database.
Guide change history
Updates to this SupplementSafety.org guide.
Minor updates
Updated guide wording, organization, and source presentation. Added our editorial change history.
Initial release
Initial SupplementSafety.org guide prepared from source reference material.
Validation: Not yet completed. Editorial updates do not constitute clinical validation.
Sources
Source information
This guide organizes source material about uses, preparations, amounts, and precautions. Read the conditions alongside each statement; the information may apply only to particular preparations or populations.
The source document includes supporting references. We have not independently summarized or assessed every cited study for this guide.
- Source document version
- June 26, 2026
- Source captured
- Aug 15, 2026
- Editorial work
- Editorial preparation. Independent clinical review has not been recorded for this guide.
Full citations are available through the link above. Verification is required to open them; reading this guide does not require verification.
Taking a medication too?
Explore our supplement–medication interaction checker. Its coverage and review status are shown with the results; a missing finding does not establish that a combination is safe.