Is there such a thing as an "onion worthless supplement"?
No supplement is marketed as "onion worthless," which appears to be a likely typo or autocorrect error for "onion waterless" (dehydrated onion extract) or possibly "onion wortless" (a misphrasing of onion-based herbal products). Assuming you mean onion supplements derived from Allium cepa (onions), these exist as capsules, powders, or extracts claiming benefits like heart health support from quercetin and sulfur compounds.[1]
What health claims do onion supplements make?
Manufacturers promote them for:
- Lowering cholesterol and blood pressure via antioxidants.
- Reducing inflammation and supporting immunity.
- Aiding blood sugar control in prediabetes.
These stem from onion's natural compounds like allicin (similar to garlic) and flavonoids, studied in small trials showing modest LDL cholesterol drops (5-10%) after 8 weeks.[2][3]
Is there evidence they work?
Limited. A 2019 meta-analysis of 9 trials (487 participants) found onion extract reduced total cholesterol by 15 mg/dL but had no significant blood pressure effect.[4] Animal studies suggest anti-inflammatory benefits, but human data is inconsistent—many trials are small, short-term, or industry-funded. No strong proof for immunity or diabetes claims. The NIH rates onion as "possibly ineffective" for most uses beyond basic nutrition.[5]
Are onion supplements safe to take?
Generally yes for healthy adults at 600-1200 mg/day:
- Common side effects: stomach upset, gas, heartburn (worse raw/on empty stomach).
- Rare risks: bleeding issues if on blood thinners (due to antiplatelet effects); allergies in onion-sensitive people.
- Avoid if pregnant, breastfeeding, or pre-surgery. Interact with diabetes meds (may lower blood sugar too much).[6]
Start low, consult a doctor—especially with conditions or meds.
How do they compare to eating onions?
Fresh onions provide similar compounds with fiber and fewer additives. A medium onion (110g) delivers ~20mg quercetin vs. 100-500mg in supplements. Eating 1-2 daily matches benefits without processing risks, per observational studies linking onion intake to 15-20% lower heart disease risk.[7]
Should you buy onion supplements?
Skip unless diet lacks alliums—evidence is weak, and whole foods are cheaper/safer. Look for third-party tested brands (USP/NSF) to avoid contaminants. Cost: $10-20/month.
Sources
[1] WebMD: Onion
[2] Phytother Res: Onion meta-analysis (2019)
[3] J Ethnopharmacol: Onion review
[4] Phytother Res meta-analysis
[5] NIH NCCIH: Onion (archived)
[6] Mayo Clinic: Onion safety
[7] Nutrients: Allium intake and CVD