Diallyl Disulfide — DADS (Garlic Polysulfide · Antimicrobial · Phase-II Induction)
| Compound | Diallyl Disulfide (DADS) |
| Chemical class | Organosulfur — Polysulfide (Diallyl disulfide) |
| CAS | 2179-57-9 |
| Primary source | Allium sativum (garlic) — primary volatile organosulfur in garlic oil |
| Key applications | Antimicrobial, antifungal, Phase-II enzyme induction, anticancer, garlic odour active |
| Claim strength | Moderate |
| Typical form | Garlic oil (DADS 57–60%); garlic oil softgels; DADS isolate |
| Buy from Herbuno | Garlic Oil Soluble Extract - Allium sativum → |
Name origin: Di- (two) + allyl (prop-2-enyl groups) + disulfide (two sulfur atoms linked: —S—S—). DADS is the primary volatile organosulfur compound in steam-distilled garlic essential oil, formed from allicin degradation (allicin → DADS + other polysulfides). It is responsible for much of garlic’s characteristic persistent odour and is the most abundant single compound in garlic oil. Traditional use: Garlic oil preparations have been used traditionally across all cultures that use garlic medicinally, including for topical wound antisepsis, ear infections, and respiratory preparations. The oil form concentrates the volatile organosulfur compounds (DADS, DATS, DAS) relative to water-based extracts which are richer in alliin and SAC. Research trajectory: DADS has documented antimicrobial, antifungal (including Candida), Phase-II enzyme inducing (Nrf2/GST/NQO1), and antiproliferative activities in preclinical research. It induces cell cycle arrest (G2/M) and apoptosis in cancer cell lines. DADS is more stable than allicin and more readily extracted into oil-based formulations. Commercial source: Garlic Extract Powder and Garlic Oil Soluble Extract from Herbuno deliver DADS as the primary oil-soluble organosulfur constituent. See sourcing options below.
Evidence for DADS Applications
Antimicrobial and antifungal: DADS demonstrates broad-spectrum antibacterial activity (MIC 0.05–1 mg/mL against S. aureus, E. coli, H. pylori, Pseudomonas aeruginosa) and potent antifungal activity against Candida albicans, Aspergillus, and dermatophytes. Mechanism: reaction with thiol groups of essential microbial enzymes (thiol-disulfide exchange) — same as allicin but DADS is more stable in formulations. Claim strength: Moderate.
Phase-II enzyme induction (Nrf2): DADS activates Nrf2 and induces Phase-II detoxification enzymes (GST, NQO1, HO-1) in liver and intestinal cells. In animal models, DADS pre-treatment significantly reduces carcinogen-induced DNA adduct formation. The Phase-II enzyme induction profile is relevant for chemopreventive supplement positioning alongside sulforaphane and PEITC. Claim strength: Moderate.
Antiproliferative: DADS induces G2/M cell cycle arrest and apoptosis in colon, breast, and prostate cancer cell lines via multiple mechanisms: Cdc2/cyclin B1 inhibition, caspase activation, and ROS generation. In animal carcinogenesis models, dietary DADS reduces tumour incidence and burden. Claim strength: Moderate (preclinical convergent).
H2S generation (cardiovascular): DADS and other garlic polysulfides generate hydrogen sulfide (H2S) under physiological conditions via reaction with glutathione. H2S is a gasotransmitter that promotes vasodilation, reduces blood pressure, and has cardioprotective effects — the same mechanism as DATS but with lower H2S yield per molecule than the trisulfide. Claim strength: Moderate.
Garlic Oil Soluble Extract - Allium sativum →
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Dosage & Formulator Specification
No established isolated DADS human supplement dose. Garlic oil preparations (60–90 mg garlic oil/day, delivering approximately 35–55 mg DADS) are the standard commercial form for DADS delivery. Garlic oil softgels are the most common formulation for oil-soluble garlic organosulfur compounds. Request DADS content by GC on CoA for oil-based garlic preparations. DADS is volatile — encapsulation (softgel, enteric-coated) is required for effective delivery and to reduce garlic breath. DADS is more stable in oil than aqueous environments — lipid-based delivery is preferred over aqueous extract for DADS-focused formulations.
Frequently Asked Questions — DADS
What is the difference between DADS, DATS, and DAS?
Diallyl monosulfide (DAS), diallyl disulfide (DADS), and diallyl trisulfide (DATS) are a homologous series of garlic organosulfur compounds differing in the number of sulfur atoms in the polysulfide chain. DAS (one sulfur): mildest, weakest activity. DADS (two sulfurs): moderate potency, primary garlic oil volatile. DATS (three sulfurs): most potent for antimicrobial, antiproliferative, and H2S generation; highest H2S yield per molecule. In garlic oil, DADS typically constitutes 55–65%, DATS 20–30%, and DAS 5–10%.
Why does garlic breath persist so long after eating raw garlic?
DADS and related volatile polysulfides are absorbed from the GI tract into the bloodstream and excreted via the lungs (pulmonary excretion) over 24–36 hours — significantly longer than their GI transit time. This pulmonary excretion of volatile organosulfur compounds is the source of persistent garlic breath. Enteric-coated garlic supplements reduce immediate GI malodour but do not prevent systemic absorption and subsequent pulmonary excretion of volatile organosulfur compounds.
Is DADS effective against H. pylori?
In vitro, DADS has potent anti-H. pylori activity (MIC 0.05–0.2 mg/mL). Several small human trials with garlic preparations have shown reductions in H. pylori breath test scores. However, achieving antimicrobially effective DADS concentrations at the gastric mucosa with oral supplementation is limited by gastric absorption before reaching mucosal target sites. Results in human trials are inconsistent — garlic is not a substitute for antibiotic triple therapy but may have an adjunct role for H. pylori suppression in conjunction with standard treatment.
Can DADS in garlic oil be used topically?
Yes — garlic oil (high DADS content) has traditional and some clinical use for topical applications including ear infections (otitis media in children, several randomised studies), tinea capitis, and cutaneous fungal infections. For topical use, garlic oil diluted 1:1 in olive oil or other carrier reduces irritation while delivering DADS antimicrobial activity. Undiluted garlic oil can cause chemical burns — always dilute for direct skin contact.
Related compounds: Allicin, Diallyl Trisulfide, Alliin, Ajoene
Claim-strength scale – High = multiple human RCTs; Moderate = limited trials or strong preclinical convergence; Emerging = early-stage lab or animal data.
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