# Sainfoin

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/sainfoin
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-30
**Evidence Score:** 4 / 10
**Category:** Compound
**Also Known As:** Onobrychis viciifolia, Holy clover, French grass, Cock's head, Esparcet, Fitching, Common sainfoin

## Overview

Sainfoin (Onobrychis viciifolia) is a leguminous forage plant rich in condensed tannins, particularly prodelphinidins and procyanidins, which exert anthelmintic effects by binding to and precipitating larval proteins of gastrointestinal nematodes. These polyphenolic tannins interfere with parasite motility and hatching by disrupting cuticle integrity and inhibiting key [digestive enzyme](/ingredients/condition/gut-health)s in nematode larvae.

## Health Benefits

• Anthelmintic activity: Demonstrates significant inhibition of gastrointestinal nematode larvae in animal studies, with sainfoin reducing fecal egg hatching rates by 26.9% in rabbits (PMID: 28215185) - preliminary evidence only
• [Digestive health](/ingredients/condition/gut-health) support: May help control intestinal parasites through condensed tannin activity that inhibits larval feeding of Cooperia oncophora and Ostertagia ostertagi - in vitro evidence only
• Nutritional safety profile: Shows no adverse effects on organ structure in rats at 5-10% dietary inclusion (PMID: 39055202) - animal evidence only
• Potential [antioxidant](/ingredients/condition/antioxidant) support: Analyzed for antioxidant parameters in lambs with gastrointestinal infections (PMID: 35335625) - preliminary animal data
• Possible blood parameter normalization: Demonstrated reduction in elevated creatinine, ALT, and mineral levels toward normal ranges in rats - limited animal evidence

## Mechanism of Action

Sainfoin's condensed tannins, primarily prodelphinidins and procyanidins, bind irreversibly to larval surface proteins and gut enzymes of gastrointestinal nematodes such as Haemonchus contortus and Trichostrongylus colubriformis, precipitating structural proteins and disrupting larval motility. These tannins also inhibit [acetylcholine](/ingredients/condition/cognitive)sterase activity in nematodes, impairing neuromuscular coordination. Additionally, condensed tannins form complexes with dietary proteins in the rumen/intestinal environment, potentially modulating the nitrogen balance and reducing ammonia production via inhibition of microbial urease.

## Clinical Summary

Evidence for sainfoin's anthelmintic effects comes primarily from in vitro larval development assays and small animal feeding trials, not human clinical trials. A controlled rabbit study (PMID: 28215185) demonstrated a 26.9% reduction in fecal egg hatching rates following sainfoin supplementation, representing statistically significant but modest efficacy. Studies in ruminants, particularly sheep and goats fed sainfoin hay or pellets, have shown reductions in fecal egg counts of 20–40% for Haemonchus contortus infections, though sample sizes are typically small (n=10–30 per group). Overall, the evidence base is preliminary and largely restricted to veterinary contexts, with no published human randomized controlled trials to date.

## Nutritional Profile

Sainfoin (Onobrychis viciifolia) is a leguminous forage plant with a nutritional profile characterized primarily by its condensed tannin (proanthocyanidin) content, which ranges from approximately 20–50 g/kg dry matter (DM), varying by plant part, maturity, and cultivar. Crude protein content is relatively high at 150–200 g/kg DM, comparable to other legume forages, with a favorable amino acid profile including lysine and methionine. Crude fiber (NDF) ranges from 350–450 g/kg DM, with ADF approximately 250–320 g/kg DM, supporting digestive motility. Ether extract (fat) is low at approximately 20–30 g/kg DM. Key minerals include calcium (10–15 g/kg DM), phosphorus (2.5–4.0 g/kg DM), magnesium (1.5–2.5 g/kg DM), and potassium (15–25 g/kg DM). The condensed tannins are predominantly B-type proanthocyanidins composed of epicatechin and catechin units; these tannins form complexes with proteins in the rumen/gut, which paradoxically improves protein bioavailability by reducing rumen degradation ('bypass protein' effect) while simultaneously inhibiting parasite larval development. Sainfoin also contains flavonoids including quercetin and kaempferol glycosides at low concentrations (~1–3 g/kg DM), as well as small amounts of isoflavones (formononetin, biochanin A) at levels considerably lower than red clover. Metabolizable energy is estimated at 8–10 MJ/kg DM. Bioavailability note: Unlike high-tannin plants that impair nutrient absorption, sainfoin's moderate condensed tannin levels appear to enhance rumen-bypass protein utilization without causing antinutritional effects at typical intake levels.

## Dosage & Preparation

Animal studies have used: sainfoin seed inclusion at 5-10% of total diet (rats), extract concentrations of 10-40 μg/ml (in vitro), and condensed tannin fractions at 2-10 μg/ml. No human dosage recommendations exist. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Sainfoin is generally regarded as safe when consumed as a food-grade forage or standardized extract, as it has centuries of use as a livestock feed with no documented systemic toxicity at dietary doses. Unlike other tannin-rich plants such as sorghum or oak, sainfoin's condensed tannins are not associated with hepatotoxicity or nitrate accumulation, and bloat risk in ruminants is significantly lower than with other legumes. No formal drug interaction studies exist in humans; however, the protein-binding capacity of condensed tannins may theoretically reduce oral bioavailability of co-administered medications, particularly iron supplements and basic drugs. Sainfoin supplementation during pregnancy or lactation has not been studied in humans, and caution is advised until safety data are available.

## Scientific Research

Current evidence is limited to animal studies and in vitro assays, with no human clinical trials identified. Key studies include a rat safety evaluation (PMID: 39055202) showing no adverse effects at 5-10% dietary inclusion, and a rabbit study (PMID: 28215185) demonstrating reduced nematode egg development. In vitro research (PMID: 23639199) confirmed anthelmintic effects correlating with condensed tannin content.

## Historical & Cultural Context

No information regarding traditional medicinal use was provided in the available research. Sainfoin has been primarily studied as an agricultural forage crop with potential antiparasitic properties for livestock.

## Synergistic Combinations

Other antiparasitic herbs, [digestive enzyme](/ingredients/condition/gut-health)s, probiotics, oregano oil, black walnut

## Frequently Asked Questions

### What are the active compounds in sainfoin responsible for its antiparasitic effects?

The primary bioactive compounds in sainfoin are condensed tannins, specifically prodelphinidins and procyanidins, which constitute roughly 2–6% of dry weight depending on harvest stage. These polyphenols bind to larval cuticle proteins and inhibit acetylcholinesterase in nematode species such as Haemonchus contortus, disrupting motility and hatching without the systemic toxicity associated with synthetic anthelmintics.

### Is sainfoin effective against intestinal parasites in humans?

Currently, there is no published human clinical trial data supporting sainfoin's use as an anthelmintic in humans. All significant anthelmintic evidence comes from in vitro larval assays and animal studies in rabbits, sheep, and goats, where fecal egg count reductions of 20–40% have been observed. Human application remains speculative and should not be used as a substitute for evidence-based antiparasitic therapy.

### What is the effective dose of sainfoin for anthelmintic activity in animals?

Animal studies have typically used sainfoin provided as fresh forage, hay, or pellets constituting 30–100% of the diet, with condensed tannin intake estimated at 10–30 g per day in sheep. A specific threshold intake of condensed tannins above approximately 20 g/day appears necessary for measurable reductions in fecal egg counts in ruminant models. No standardized human dosage has been established, as no clinical trials have been conducted.

### Does sainfoin interact with any medications or supplements?

No formal pharmacokinetic interaction studies exist for sainfoin in humans; however, condensed tannins are well-documented to bind dietary proteins and alkaline molecules, potentially reducing the oral absorption of iron, certain antibiotics, and drugs with basic functional groups if taken simultaneously. It is advisable to separate sainfoin supplementation from medication administration by at least one to two hours as a precautionary measure. Individuals on anticoagulants or antiparasitic medications should consult a healthcare provider before use.

### How does sainfoin differ from other tannin-containing supplements like grape seed extract?

While both sainfoin and grape seed extract are rich in condensed tannins (procyanidins), sainfoin's tannin profile is dominated by prodelphinidins with a higher mean degree of polymerization, which correlates with stronger protein-precipitation and anthelmintic activity compared to the smaller oligomeric procyanidins prevalent in grape seed extract. Grape seed extract is primarily studied for cardiovascular and antioxidant benefits via modulation of NF-κB and VEGF pathways, whereas sainfoin research is focused on gastrointestinal parasite inhibition. The two supplements have distinct research bases and should not be considered interchangeable.

### What is the current level of clinical evidence for sainfoin's antiparasitic effects in humans?

The evidence for sainfoin's antiparasitic activity remains preliminary, with most robust data coming from animal studies showing a 26.9% reduction in fecal egg hatching in rabbits. Clinical trials in human populations are limited, and while the condensed tannin mechanism is well-characterized, human efficacy and optimal dosing have not been established through rigorous clinical research. Sainfoin should not be considered a proven treatment for human parasitic infections without additional clinical evidence.

### Is sainfoin safe for use in children or pregnant women?

Safety data for sainfoin in children and pregnant women is insufficient, and use in these populations cannot be recommended without adequate clinical research. The tannin content in sainfoin may affect nutrient absorption, which is a particular concern during pregnancy and childhood when nutritional needs are elevated. Pregnant women and parents considering sainfoin for children should consult a healthcare provider before use.

### Can I obtain sainfoin's antiparasitic compounds through food sources, or is supplementation necessary?

Sainfoin (Onobrychis viciifolia) is a legume plant used primarily as livestock forage and is not commonly consumed as a food by humans. While the condensed tannins responsible for antiparasitic activity are present in the plant, practical dietary intake of sainfoin in meaningful amounts would be difficult without dedicated supplementation. If considering sainfoin for parasitic support, supplement forms are the primary option available to consumers.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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