Silk Amino Acids (Silk Peptide)

Also called silk amino acid, SAA, silk peptide, silk protein hydrolysate, silk fibroin hydrolysate, fibroin peptide.

Best grade C across 3 graded outcomes Amino acid Last checked

The short answer

From 5 sources

Silk amino acids are hydrolysed silk proteins sold for immunity, memory and skin. One Korean trial, using product from its maker, found 8 weeks of a silk peptide raised natural killer cell activity in 118 adults, and a small company-funded trial reported memory gains. Evidence is thin, and no regulatory agency has reviewed safety.

Every graded outcome on this page

3 rows · line = participants
  1. Grade CNatural killer (NK) cell activityImmune markersn 118
  2. Grade DMemory test scores (Rey-Kim Memory Test)Memoryn 76
  3. Grade DBowel movement frequency in constipationConstipationn 50

Key facts

What it is
Peptides and amino acids from enzymatically hydrolysed silk proteins (fibroin or sericin from Bombyx mori cocoons)24
Immune marker
Silk peptide Sil-Q1 at 7.5 g/day for 8 weeks raised NK cell cytotoxicity vs placebo in 118 Korean adults (grade C)1
Memory
A fibroin hydrolysate at 280 to 600 mg/day for 3 weeks improved memory test scores in a 76-person, four-arm trial funded by its developer (grade D)2
Safety data
Sericin-derived peptides up to 1.8 g/day for 8 weeks caused only occasional mild gastrointestinal symptoms in healthy adults4
Agency safety reviews
No ODS, NCCIH, LactMed, LiverTox, Health Canada or EMA source covers silk amino acids5

What it is

Silk amino acids are peptides and amino acids made by enzymatically breaking down silkworm silk proteins such as fibroin and sericin.

How it works

Proposed

Trial authors measured higher NK cell cytotoxicity and IL-12 after silk peptide supplementation, and dose-related memory score changes after a fibroin hydrolysate. How silk peptides would produce these effects is not established in people.12

Forms, side by side

3 forms named in our sources. The rest show what our data holds, and say plainly where it holds nothing yet.

Silk Amino Acids (Silk Peptide) forms compared

3 forms
Silk Amino Acids (Silk Peptide) forms compared: 3 forms by 3 attributes. Empty cells are labelled No data yet, or Not graded in the evidence row.
3 formsSilk peptide powder (Sil-Q1)Silk fibroin enzymatic hydrolysateSericin-derived oligopeptides
Absorption in peopleNo human absorption data in our sources.1No human absorption data in our sources.2No human absorption data in our sources.4
GI toleranceThe trial authors describe it as safe at 7.5 g/day for 8 weeks.1No adverse effects were reported at up to 600 mg/day for 3 weeks.2In 42 randomized healthy adults, up to 1.8 g/day for 8 weeks caused no serious adverse events; lab values stayed normal, with occasional mild, transient gastrointestinal symptoms.4
Studied forNK cell activity (7.5 g/day)Memory test scores (280 to 600 mg/day)Short-term safety and gut bacteria
  1. Silk peptide powder (Sil-Q1)
    Absorption in people
    No human absorption data in our sources.1
    GI tolerance
    The trial authors describe it as safe at 7.5 g/day for 8 weeks.1
    Studied for
    NK cell activity (7.5 g/day)
  2. Silk fibroin enzymatic hydrolysate
    Absorption in people
    No human absorption data in our sources.2
    GI tolerance
    No adverse effects were reported at up to 600 mg/day for 3 weeks.2
    Studied for
    Memory test scores (280 to 600 mg/day)
  3. Sericin-derived oligopeptides
    Absorption in people
    No human absorption data in our sources.4
    GI tolerance
    In 42 randomized healthy adults, up to 1.8 g/day for 8 weeks caused no serious adverse events; lab values stayed normal, with occasional mild, transient gastrointestinal symptoms.4
    Studied for
    Short-term safety and gut bacteria
Every cell holds data from a cited page; citation numbers link to the page that holds them.Scroll the table for every column

What the human research says

Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.

Trial map

3 graded outcomes, largest study first

All 3 graded outcomes found an improvement. The largest, a 2021 randomized trial of 118 people on natural killer (NK) cell activity, found an improvement.

Bar: the ages a study enrolled (running to the edge when it states no upper or lower limit). Dot: only a mean age, counted as near your age within 5 years. Tick: the mean age inside a range.

3Bowel movement frequency in constipation: improved, 23–71

2Memory test scores (Rey-Kim Memory Test): improved, 28–92

1Natural killer (NK) cell activity: improved, ages not stated

1. Natural killer (NK) cell activity: improved, 118 people12. Memory test scores (Rey-Kim Memory Test): improved, 76 people23. Bowel movement frequency in constipation: improved, 50 people3

1Natural killer (NK) cell activity

Improved · Grade C · RCT, 118 people, 2021

Korean adults (130 randomized, 118 analysed)

Dose, result and source
Every graded outcome on this page, largest study first
OutcomeFoundPeopleStudyWho was studied
Natural killer (NK) cell activityImproved118Grade C · RCT, 2021Korean adults (130 randomized, 118 analysed)
Memory test scores (Rey-Kim Memory Test)Improved76Grade D · RCT, 2018Healthy Korean adults aged 28 to 92, average about 55 (76 randomized to 4 arms; 15 dropped for non-compliance)
Bowel movement frequency in constipationImproved50Grade D · RCT, 2024Adults aged 23 to 71 with fewer than 5 bowel movements a week
Each circle is one graded outcome on this page, numbered from the largest study down, and placed by how many people it studied (log scale). By age shows the ages each study enrolled, where it states them. It shows who was studied and what was found, not advice about your dose.

Every graded row

3 rows
Grade CNatural killer (NK) cell activityImmune markersImprovedRCT
n 118 · 2021

Improved NK cell cytotoxicity rose within the silk peptide group at all four effector-to-target ratios, and the change differed from placebo at three of them; IL-12 rose more than with placebo. Infection outcomes were not reported in the abstract.

Design
RCT, n = 118, 2021
Population
Korean adults (130 randomized, 118 analysed)
Form
Silk peptide (Sil-Q1)
Dose
7.5 g/day
Duration
8 weeks
Source
Reference 1 · PubMed 34578808 (opens PubMed)
Grade DMemory test scores (Rey-Kim Memory Test)MemoryImprovedRCT
n 76 · 2018

Improved Memory quotient, learning gradient, words remembered, retrieval efficiency and drawing/recall rose dose-dependently vs placebo, with a plateau at 400 to 600 mg/day. No adverse effects were reported.

Design
RCT, n = 76, 2018
Population
Healthy Korean adults aged 28 to 92, average about 55 (76 randomized to 4 arms; 15 dropped for non-compliance)
Form
Silk fibroin protein enzymatic hydrolysate (FPEH)
Dose
280, 400 or 600 mg/day in two doses
Duration
3 weeks
Source
Reference 2 · PubMed 29462997 (opens PubMed)
Grade DBowel movement frequency in constipationConstipationImprovedRCT
n 50 · 2024

Improved Average weekly bowel movements rose to 1.4 times baseline, significantly more than with placebo, alongside shifts in gut bacteria.

Design
RCT, n = 50, 2024
Population
Adults aged 23 to 71 with fewer than 5 bowel movements a week
Form
Sericin/fibroin mixture drink fermented with Lactococcus lactis BM32-1
Dose
100 mL/day
Duration
12 weeks
Source
Reference 3 · PubMed 38966048 (opens PubMed)

What the numbers add up to

Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.

Three ingredients, one name

"Silk amino acids" covers different products: the immune data come from one silk peptide powder, the memory data from one fibroin hydrolysate, and the safety data from sericin peptides. None of these results has been repeated in another trial among our sources.124

How we got this: Products named in each abstract

Studied doses

Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.

Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.

Doses studied in human trials

Doses studied in human trials ranged from 280 mg a day of a silk fibroin hydrolysate for 3 weeks to 7.5 g a day of a silk peptide powder for 8 weeks; a fermented sericin/fibroin drink was given at 100 mL a day for 12 weeks.123

Interactions and safety

Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.

Interactions

0 agents

None found in our sources.

Check with what you take

Kept on this device only

Add what you take. We list every interaction our evidence profiles cite between Silk Amino Acids and your picks, and between your picks.

Most cited:

Add a supplement or medicine you take to check it against Silk Amino Acids.

Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.

Not medical advice, and no dosing advice. An empty result means no row we cite names that pair, by name or through a drug class we can link the medicine to, not that a combination is safe. Where our sources name only a group of medicines we cannot match, the cabinet says so. Ask your pharmacist before you combine supplements and medicines.

Who should be careful

3 groups
People on medicines
No ODS, NCCIH, LactMed, LiverTox, Health Canada or EMA source covers silk amino acids. NCCIH notes that dietary supplements may interact with medications.5
Pregnancy, breastfeeding and children
No trial studied these groups, and NCCIH notes that many dietary supplements have not been tested in pregnant women, nursing mothers or children.5
Before surgery
NCCIH advises telling your health care providers about all supplements well before an operation.5
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.

How to read the label

What to check on the Supplement Facts panel.

How to read the label

2 checks
Products are not interchangeable

The trials used three different proprietary ingredients: a silk peptide powder, a fibroin hydrolysate and sericin oligopeptides.124

Label dose vs clinical dose

Compare the label amount with 7.5 g/day (immune-marker trial) or 280 to 600 mg/day (memory trial) of the specific ingredient tested.12

Have the bottle? Photograph its Supplement Facts panel and see each line, silk amino acids (silk peptide) included, beside the doses and forms the trials used in Label X-Ray.

Frequently asked questions

Short answers to common questions; the numbers link to the sources below.

Common questions

7 answers
Do silk amino acids boost immunity?

One 8-week trial of a silk peptide at 7.5 g a day raised NK cell activity, a lab immune marker, compared with placebo in 118 adults. The abstract does not report on infections.1

Do they improve memory?

A 3-week trial funded by the ingredient's developer reported dose-related memory score gains at 280 to 600 mg a day of a fibroin hydrolysate, with only about 15 people per group.2

Are silk amino acids safe?

Short trials of up to 12 weeks reported no serious problems, with occasional mild stomach symptoms for sericin peptides. No federal or regulatory review covers them.145

How much was used in studies, and for how long?

Doses ranged from 280–600 mg a day of a fibroin hydrolysate for 3 weeks to 7.5 g a day of a silk peptide powder for 8 weeks; a fermented silk drink was given at 100 mL a day for 12 weeks, and a safety trial used 0.9 or 1.8 g a day of sericin-derived oligopeptides for 8 weeks. Each trial tested a different ingredient.1234

Do silk amino acids interact with medicines?

We found no published interaction studies or reports for silk amino acids. NCCIH notes that dietary supplements in general may interact with medications.5

Are silk amino acids safe in pregnancy or breastfeeding?

No trial has included pregnant or breastfeeding women, and NCCIH notes that many supplements have not been tested in these groups.5

What are silk amino acids?

Peptides and amino acids made by enzymatically breaking down silkworm silk proteins such as fibroin and sericin.24

Sources

5 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.

Sources cited on this page

5 sources
  1. 1Supplementation with a Natural Source of Amino Acids, Sil-Q1 (Silk Peptide), Enhances Natural Killer Cell Activity: A Redesigned Clinical Trial with a Reduced Supplementation Dose and Minimized Seasonal Effects in a Larger Population.RCT Nutrients, 2021 · PMID 34578808
  2. 2Effect of a Fibroin Enzymatic Hydrolysate on Memory Improvement: A Placebo-Controlled, Double-Blind Study.RCT Nutrients, 2018 · PMID 29462997
  3. 3Silk-derived sericin/fibroin mixture drink fermented with plant-derived Lactococcus lactis BM32-1 improves constipation and related microbiota: a randomized, double-blind, and placebo-controlled clinical trial.RCT Biosci Microbiota Food Health, 2024 · PMID 38966048
  4. 4Safety, Tolerability, and Gut Microbiota Impact of Sericin-Derived Oligopeptides (SDOs) from Yellow Silk Cocoons in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Trial.RCT Foods, 2026 · PMID 42450525
  5. 5Using Dietary Supplements WiselyFact sheet National Center for Complementary and Integrative Health (NCCIH), 2019 · nccih.nih.gov

What changed

Every dated change to this page: what changed, who made it and why.

Change log

2 entries
Dated changes to this page
DateChangeWho and why
FAQ, related linksSearched PubMed for 2023–2026 human trials and meta-analyses of silk peptides, fibroin and sericin: none beyond those already cited. Checked PubMed and LactMed for interactions: none listed, noted in the FAQ. Added three FAQs (studied doses and duration, interactions, pregnancy) and a link to the immune goal page. Fact-checked against the sources; corrected: the dose answer now includes the 2026 sericin-oligopeptide safety trial, and the interaction answer says we found no reports rather than that none exist.Writer: Kymata Health EditorialTrigger: A–Z page audit
allInitial editorial evidence review. Every PMID checked against NCBI E-utilities esummary (title and year) and each cited abstract read; numbers taken from the abstracts (and, where noted, the full text for funding and participant counts). Industry links disclosed: WORLDWAY Co. conceived and supplied Sil-Q1 (2021); BrainOn Inc. funded the 2018 memory trial. No agency source covers silk amino acids, so safety text cites NCCIH's Using Dietary Supplements Wisely. Where to buy: we didn’t list a product; none of the stores we checked on 2026-10-15 sells it.Writer: Kymata Health EditorialTrigger: new page

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