Which large, independent randomized trials of aged garlic extract are currently registered or underway?
Executive summary
A search of the recent literature and trial registries shows several randomized trials of aged garlic extract (AGE) that are registered or reported in the last decade, but few that meet the bar of "large, independent, randomized" and ongoing; many are single-center, short (6–12 week) trials or industry-linked studies and systematic reviews call for bigger, longer, independent trials to settle efficacy and safety questions [1] [2] [3]. The clearest, relatively large randomized trials identified include coronary atherosclerosis studies led by Budoff and collaborators, a registered inflammation/obesity trial (NCT01959646), and a registered trial in women focused on IL‑6 and cardiovascular risk (NCT03860350), while multiple dose‑response and hypertension trials are smaller or population-limited and meta-analysts explicitly note heterogeneity and the need for larger independent trials [4] [5] [6] [7] [3].
1. The Budoff atherosclerosis trial: the closest thing to a large, randomized cardiovascular study
A multicenter randomized trial led by Michael J. Budoff and colleagues evaluated AGE (often combined with co‑supplements like coenzyme Q10, B vitamins, folic acid and L‑arginine in some arms) for progression of coronary artery calcification and surrogate markers of atherosclerosis, and is reported as a randomized clinical trial with notable sample size and imaging endpoints — this is the principal example cited as a sizable AGE cardiovascular outcome trial [4]. The paper and its full text describe randomized allocation and use of objective imaging to track subclinical atherosclerosis, which places it among the more robust AGE trials to date, although reporting shows concomitant nutraceuticals in some formulations, complicating attribution to AGE alone [4].
2. Registered clinical trials: NCT01959646 and NCT03860350 — registered and reported but not blockbuster‑sized
An AGE trial registered as NCT01959646 studied immunologic and inflammatory endpoints in adults with obesity and reported modulation of immune markers and lipid changes after six weeks of AGE supplementation, and this registration is explicitly cited in the published trial report [5] [1]. Another registered randomized trial, NCT03860350, examined AGE supplementation in females with low cardiovascular risk and reported reductions in IL‑6; the trial is registered and the published report cites that identifier [6] [8]. Both trials are randomized placebo‑controlled studies and listed in registries, but neither is described in the sources as a large, multicenter endpoint trial on hard outcomes like myocardial infarction or stroke [1] [6].
3. Hypertension dose‑response trials and small single‑center RCTs — consistent signals but limited scale
Multiple randomized trials have tested AGE for blood‑pressure lowering effects, including a dose–response trial registered in the Australian New Zealand registry (ACTRN12611000581965) and several 12‑week RCTs showing SBP reductions in hypertensive populations; these trials support biological plausibility but are generally limited to weeks or months and modest sample sizes [7] [9] [10]. Systematic reviews and meta‑analyses summarized these RCTs but emphasized heterogeneity in populations, AGE preparations, and trial sizes and called for larger, longer, independent trials to confirm clinical benefit [3] [11].
4. Independence and conflicts: industry formulations and heterogeneity matter
A consistent limitation across the literature is variability in AGE products (Kyolic and other proprietary preparations are repeatedly named) and in some trials AGE was combined with other supplements, which raises questions about independence and attribution of effects to AGE alone; reviews and analytical pieces note this heterogeneity and the need for independent trials using standardized AGE preparations [12] [13] [4]. Author groups and registries show mixed funding and authorship patterns in the published RCTs; meta‑analysts explicitly flag potential biases and call for large, independent, long‑duration randomized trials to settle efficacy and safety [3] [11].
5. What the current record actually says and what it does not
The current record shows registered randomized AGE trials that are published and report favorable biomarker and surrogate outcomes (NCT01959646, NCT03860350, Budoff et al.), and multiple smaller RCTs for hypertension and inflammation, but there is no incontrovertible evidence in these sources of several concurrent, large (>1,000 participant), independent, multicenter randomized outcome trials underway testing AGE on hard clinical endpoints; systematic reviewers highlight that gap and call for such trials [4] [3] [2]. The sources do not provide a live registry snapshot confirming ongoing recruitment status for every trial; therefore this synthesis reports what is registered and published in the available literature and notes the limitation that up‑to‑the‑minute registry statuses were not provided in the supplied material [8] [6].