NAC N-Acetyl Cysteine Drops, 600 mg Antioxidant Amino Acid Supplement

Six-dimension breakdown

Why this scored 52/100

This NAC drops product delivers 600mg NAC per serving in a liquid format under a small herbal-supplements label. NAC has a strong evidence base at 600-1200mg/day (Poe 2004 for respiratory, Grandjean 2013 for glutathione precursor supplementation) and is FDA-approved as an intravenous agent for acetaminophen overdose. However, NAC in a liquid drop delivery format is unusual and raises stability questions — NAC is prone to oxidation and off-taste (sulfurous), which is why nearly all clinical NAC products are enteric-coated capsules or effervescent tablets. Delivering 600mg NAC as a liquid means either a very large volume per dose or a low actual delivered dose after oxidation losses. The small-label brand behind this SKU does not publish stability data or third-party COAs. Also relevant: the FDA sent warning letters in 2020-2022 questioning whether NAC could be sold as a dietary supplement (the ingredient was studied as a drug first, per FD&C Act 201(ff)(3)(B)). Regulatory status is currently permissive but historically contested. Rejected for delivery-format concerns and brand transparency gaps.

Evidence & sources

The Vyvata score's Evidence dimension measures the quality of published RCT support for a product's active ingredients at the label dose. Our source hierarchy: double-blind RCTs in MEDLINE-indexed journals > single-blind RCTs > open-label trials > observational studies > mechanism papers > N=1 case studies (anecdotes). Predatory journals and manufacturer-authored studies without independent replication are weighted down.

Product-specific evidence citations for this item are embedded in the analysis text on the "Analysis" tab. For the full framework and evidence hierarchy, see the methodology page.

How to read the Evidence dimension

• 80–100: Multiple double-blind RCTs in indexed journals directly testing this product OR the exact ingredients at the exact dose.
• 60–79: Single double-blind RCT + supporting ingredient literature at the studied dose.
• 40–59: Open-label trials + ingredient literature; no product-specific double-blind evidence.
• 20–39: Ingredient literature only; no product-specific trials or trials in predatory venues.
• 0–19: No credible evidence base or unverifiable claims.

FAQ data has not been generated for this product yet. See the site FAQ for general questions.

Customer reviews

All the data we have on this product

Every VSF-related metafield surfaced verbatim. Nothing hidden. If you spot data that looks wrong, let us know.

VSF score

52 / 100

Tier

Rejected

Category

Supplements

Subcategory

immune antioxidants

Last scored

August 29, 2026

Third-party certifications

None on record at time of scoring

Vendor

Tailor Made Herbal Products

Tags

Shopify Collective, Tailor Made Herbal Products

Every score is set from the published rubric, audit-logged, and rescored whenever new evidence emerges (published trials, updated labels, third-party testing releases). Every vendor is scored on the same criteria — no pay-to-play. See our editorial-independence disclosure for the full policy, including brands with an editorial relationship to this site.