NAC - N-Acetylcysteine (Cysteplus)

Kumar et al. 2021 (Clin Transl Med)

NAC - N-Acetylcysteine (Cysteplus)

Name: NAC - N-Acetylcysteine (Cysteplus)
Brand: Thorne HealthTech
SKU: thorne-nac
Price: 29.0 USD
Availability: InStock
Rating: 4.5 (34139 reviews)

Amino acid · Capsule · 90 portioner#4 / 11 in Amino acid

7.2

Overall score · out of 10

7.2

Overall score · out of 10

Dose vs. studies7.3

Transparency7.0

Value9.6

Community6.0

Formulation5.0

Tier 3

Ingredient RCT (matching dose)

The ingredient was tested in an RCT at the same dose this product sells.

Redaktionellt score, paid $0 No affiliate link Tested by independent lab No public analysintyg Sample received: No

How we scored this product Show the full breakdown

Dose vs. studies (55%) 7.3

Transparency (20%) 7.0

Value (10%) 9.6

Community sentiment (10%) 6.0

Formulation (5%) 5.0

Composite 7.2

7.2 composite

Dose vs. studies55%7.3

Transparency20%7.0

Value10%9.6

Community10%6.0

Formulation5%5.0

Bevisning gates dose: the evidence grade sets the ceiling, and the dose decides how much of that ceiling the product reaches. Value = inverse of price-per-trial-dose-day. Community = mean sentiment of external reviews. Säkerhet caps applied after weighting.

This score is our editorial judgment, not a scientific standard. We combine published evidence, dose, price, transparency, and consumer signals into one composite: this is our method, not a peer-reviewed clinical rating. A higher score means a product does better on the factors we weight, not that it is medically proven to work.

Read the full method →

Question 1

Does the molecule work?

The science behind each active ingredient, independent of which brand sells it.

NAC Grade B

Cysteine donor for glutathione synthesis; drug-strength efficacy for specific uses.

1 landmark RCT · US: Dietary supplement (FDA position volatile) · EU: Food supplement; drug in some countries at doses ≥200 mg

Question 2

Is this bottle good?

The specific product: dose, price, transparency, and what buyers report.

Dose vs research

83% av studiedosen

Below the full trial dose

Cost at trial dose

$0.39/day at trial dose

What one effective daily dose actually costs

Transparency

7.0/10 · No public analysintyg

Independent batch testing confirmed

Consumer signals

34,139 reviews across platforms · 4.5/5 · high confidence

Operational signal only, never used as clinical evidence

Question 3

What's the catch?

Säkerhet flags, transparency gaps, dosing concerns, and recurring buyer complaints.

No public analysintyg

Certificate of Analysis not published

Without a public analysintyg, batch purity and potency cannot be independently verified.

Buyer complaints

Trustpilot: dissatisfaction with customer service; Amazon: capsule count varies by size purchased

Recurring themes from consumer review platforms.

Best for

Budget-friendly

Avoid if

Only 83% av studiedosen, No public analysintyg

Full-dose status

83% av studiedosen

Pris/month

$10

COA status

Not public

Biggest caveat

Dose is 83% of the trial dose.

Nearest alternatives

N-Acetyl L-Cysteine (NAC) Powder BulkSupplements · Poäng 7.4
Jarrow Formulas N-A-C Sustain, 600 mg Jarrow Formulas · Poäng 7.4
NAC (N-Acetyl-L-Cysteine) 900 mg Pure Encapsulations · Poäng 6.7

The numbers

Pris

$29

per bottle · 90 portioner

Dose vs. research

Överensstämmer med studier 83%

of published effective dose

$ / day at studied dose

$0.39

what one effective daily dose costs

$ / g active

$0.64

per gram of active substance

Independently checked

Data verification

Pris

$29

Verified n/a

Dose

83% av studiedosen

Verified n/a

COA status

Not public

Verified n/a

Bevisning grade

Per-ingredient breakdown

BNAC

Verified n/a

All product data is checked against original sources. Prices, doses, and testing status are updated when product pages change. Bevisning grades are reviewed when new human RCTs are published. Read how we verify.

What's inside

Ingredient

Dose in this product

Trial dose

Bevisning

NAC

Cysteine donor for glutathione synthesis; drug-strength efficacy for specific uses.

500.0 mg 83% av studiedosen

600 mg

Consumer signals

4.5 out of 5 across 34,139 verified reviews on 4 platforms.

High confidence

Consumer sentiment compiled from 4 public sources.

Trustpilot

29 reviews · negative sentiment

Praisehigh product quality reputation overall

Complaintsdissatisfaction with customer service

ThemesThorne's direct Trustpilot page shows unhappy sentiment focused on customer service, not product quality.

Compiled from Trustpilot listing located during research; verified at build time.

Amazon

34,110 reviews · positive sentiment

Praisereduces inflammationhigh vitamin/ingredient quality

Complaintscapsule count varies by size purchased

ThemesAmazon reviewers consistently praise the ingredient quality and anti-inflammatory effects.

Compiled from Amazon listing located during research; verified at build time.

iHerb

positive sentiment

Praiseexcellent high-purity NACtrusted practitioner-grade brand

Complaintsmixed impressions reported by a few long-term users

ThemesiHerb reviewers call this an excellent, high-purity NAC supplement from a trusted brand.

Compiled from iHerb listing located during research; verified at build time.

1 threads discussed · mixed sentiment

Praisecommonly used in supplement stacks

Complaintsa subset of users report poor experiences

ThemesReddit users generally use Thorne NAC in stacks, though some report inconsistent personal results.

Compiled from Reddit listing located during research; verified at build time.

These are consumer sentiment signals. They do not measure whether the product actually works. See our evidence section for that.

Independent external anchors

Public sources on this same product, unrelated to NO1GEVITY. NIH DSLD is the US government's registered label database (shown verbatim). SuppCo.com is a separate, unaffiliated commercial site with no partnership or data-sharing arrangement with us. NO1GEVITY scores are computed independently of both.

Unaffiliated third-party site

SuppCo.com

SuppCo is a separate, unaffiliated supplement-tracking site with no partnership, data-sharing agreement, or business relationship with NO1GEVITY. We are not endorsed by them and they do not endorse us. The two facts below are individually verified against the manufacturer or NSF; the outbound link is provided only so readers can independently cross-check on a third-party site if they want to.

Tested by independent lab, YesNSF certified, Yes

NIH DSLD registered label

DSLD ID 15983, UPC 6 93749 56002 9

Portionstorlek1 Capsule(s)

Portioner per containern/a

Supplement Facts panel, verbatim

N-Acetyl-L-Cysteine500 mg

What others say, with a source hierarchy

We treat external opinion very differently depending on where it comes from. Tier A is our strongest signal. Tier C is background sentiment only. Tier Rejected is what we excluded, listed openly so you can see what we discarded.

These reviews are aggregated from third-party sources, not written by NO1GEVITY. Each entry shows its source, retrieval date, and whether the source has an affiliate or paid relationship. We do not edit reviews to change their meaning. Disclosure policy.

Tier A

Independent deep reviews, lab tests, certificates of analysis

Our strongest external evidence. Long-form independent reviews, physical-product lab work, and third-party certifications.

Innerbody, 'Best NAC Supplement' roundup

Has affiliate relationship Not a paid placement

Innerbody's 2026 comparison favors other brands over Thorne for its top NAC slot, though Thorne is a frequently recurring brand across Innerbody's broader supplement rankings for manufacturing-quality reasons.

Finding: Names Wholesome Story as best overall in its 2026 NAC rankings; Thorne's Cysteplus is not named the top pick in this specific roundup.

How we use it: Used for category-context on competitive positioning, not as an assessment specific to this SKU's dose-efficacy match.

Vår sammanfattning

Thorne's Cysteplus is a minimally-formulated 500 mg NAC capsule backed by the company's facility-wide NSF certification and internal testing program, though no per-batch COA is published for this SKU. Its per-capsule dose sits just under the 600 mg/day figure most often cited in fertility and general antioxidant RCTs, and like all NAC supplements it is currently sold in the US only under FDA's 2022 enforcement-discretion policy rather than settled legal status. The product is a reasonable, conservatively dosed single-ingredient NAC option, but buyers should not read Thorne's overall manufacturing reputation as product-specific clinical validation.

Bevisning, what actually backs this product

Longevity brands rarely test their exact finished product. We separate what's tested from what's inferred.

Strongest evidence tier

Tier 3Ingredient RCT (matching dose)

4 studies mapped

Tier 3Ingredient RCT (matching dose)

Effect of N-acetylcysteine on semen parameters and oxidative/antioxidant status (male fertility RCTs, pooled)

Multiple independent trial groups (as summarized in review literature) · 2019 · Various urology/andrology journals · 600 mg/day · 3-6 months

ingredient-levelpeer-reviewed

Improved sperm quality parameters and reproductive hormone levels versus placebo across cited trials.

600 mg/day matches Thorne's single-capsule dose closely and is within one capsule of Pure Encapsulations' 900 mg dose taken once daily; this is the strongest dose-matched signal for either product, but it is fertility-specific, not a general longevity or antioxidant claim.

Conflicts: None identified (as reported in secondary review)

Tier 4Ingredient RCT (different dose)

N-acetylcysteine improves biochemical and clinical response in patients with mild to moderate metabolic dysfunction-associated steatotic liver disease (randomiserad kontrollerad studie)

Iranian research group (MASLD RCT) · 2021 · Peer-reviewed journal (PMC-indexed) · n=69 · 600 mg, 3x/day (1800 mg/day total) · 8 weeks

ingredient-levelpeer-reviewed

No significant effect on liver enzymes or steatosis grade, but significantly increased total glutathione (552.1 to 641.9 mmol/L, p=0.003) and reduced fasting glucose, insulin, HOMA-IR, and CRP.

Dose (1800 mg/day) is double the Thorne label's single-capsule dose (500 mg) and double Pure Encapsulations' single-capsule dose (900 mg); relevant mainly as a marker of what a higher cumulative NAC dose can do metabolically, not proof either single-capsule product replicates this.

Conflicts: None identified

Tier 5Mechanistic / animal / marketing

N-Acetylcysteine: Impacts on Human Health

Elhini SH, Wu M, Bishop C, et al. (review) · 2021 · Antioxidants (MDPI) / PMC review · 400-2400 mg/day across cited trials · Varies by cited trial, weeks to months

ingredient-levelpeer-reviewed

Summarizes multiple RCTs showing NAC reduces oxidative stress markers and has modest, condition-specific benefits (COPD mucolysis, male fertility, some psychiatric adjunct use); effects are dose- and population-dependent, not uniform.

This is a narrative review, not a single trial, used here to anchor the general dose range (600 mg/day most common) and to flag that benefits are condition-specific, not a general 'detox' or longevity effect.

Conflicts: None identified

Tier 5Mechanistic / animal / marketing

Effect of Combined Glycine and N-Acetylcysteine Supplementation on Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, and Physical Function in Older Adults (GlyNAC pilot RCT)

Kumar P, Liu Y, Hyder J, et al. · 2022 · Journals of Gerontology: Series A / PMC · n=114 · 2.4 / 4.8 / 7.2 g/day combined glycine+NAC (1:1 ratio; NAC portion 1.2-3.6 g/day) · 2 weeks

ingredient-levelpeer-reviewed

Did not meet its primär endpoint of raising total glutathione across the full cohort; a post-hoc subgroup with high baseline oxidative stress and low glutathione showed an increase at medium/high doses (p=0.016).

NAC is combined with glycine here (not standalone), at doses several-fold higher than either product's per-capsule NAC amount, and the primär endpoint was negative for the overall group, this is supportive of a biological rationale, not proof that a single 500-900 mg NAC capsule raises glutathione.

Conflicts: Academic-funded (Baylor College of Medicine); no vendor sponsorship identified

NAC Kumar et al. 2021 (Clin Transl Med)

Bevisning

Research behind this product

The studies that established the trial dose and evidence grade for each active ingredient in this product. Click through to read the original paper.

Claim check, vendor claims vs. our reading of the evidence

Not medical advice. We list the strongest claims made by the brand and check each against traceable evidence.

Partial support

“NAC supplements are legal to sell in the US”

True in practice today, but only because FDA is exercising enforcement discretion (final guidance issued augusti 1, 2022) after having taken the position in 2020 that NAC is excluded from the legal definition of a dietary supplement. This is a provisional non-enforcement policy, not a settled legal green light, and could change if FDA completes rulemaking. Buyers should understand NAC's US legal status is administratively tolerated, not statutorily secure (https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-policy-regarding-n-acetyl-l-cysteine).

N/A, general market fact, not a specific vendor claim

Partial support

“Supports respiratory function and antioxidant/glutathione production (general positioning; no disease claim on page)”

The mechanistic rationale (NAC as a glutathione precursor, licensed mucolytic in several countries) is well supported in the literature, and Thorne's 500 mg dose sits close to the 600 mg/day most-studied fertility and general-use dose. But the vendor page cites no specific trial, and the strongest human RCTs are condition-specific (fertility, MASLD glutathione, COPD) rather than general wellness (https://pmc.ncbi.nlm.nih.gov/articles/PMC8234027/).

Vendor source

Regelverk status

Rules change often. We record when we last verified each row. See the full regulatory timeline →

What we could not verify

We list this openly. If a claim isn't backed by a source we can trace, we'd rather flag it than repeat it.

No per-batch public Certificate of Analysis was located for Cysteplus specifically, despite Thorne's facility-level NSF certification.
No peer-reviewed RCT was located using this exact branded product; all cited evidence is ingredient-level NAC research at various doses.
The product label recommends practitioner-directed use without a fixed self-directed daily dose, making it harder for an unsupervised buyer to map the dose to specific research findings.
Long-term (multi-year) safety data specific to daily supplemental NAC use at this dose was not identified in this review.

Important to know

NACSmells like sulfur (rotten eggs). Enteric-coated forms reduce this. Don't combine with nitrates without medical supervision.

Redaktionellt notes

A standard 500mg NAC capsule at market-typical dosing; glutathione-precursor rationale is well-established, though this SKU has no combination with glycine (the 'GlyNAC' longevity-research pairing).

In plain language

Why this scored this way

This Thorne HealthTech NAC - N-Acetylcysteine (Cysteplus) scores 7.2, making it a mid-tier product with both strengths and weaknesses. It delivers 500.0mg of NAC (83% of the 600mg trial dose) with grade B evidence (promising human data, not yet comprehensive). At $0.39/day it's priced well for what you get.

What drives the score up

Dose-evidence score of 7.3 shows decent alignment with trial doses.
Tested by independent lab (transparency 7.0).
Value score of 9.6 at $0.39/day.

What drags it down

No public analysintyg available for independent verification.
Limited consumer feedback (community score: 6.0).

Why you'd choose it

You want good value at $0.39/day.
You want NAC from a Thorne HealthTech product.
You want a tested by independent lab product.

Why you might skip it

You want a product with a publicly available CoA.

Go deeper

Where this sits

Actives inside

NAC

Kategori

Se alla in Amino acid →

Varumärke

Thorne HealthTech profile →

Jämför this product → Visit brand site →

Varumärke owners

Spot an error?

If you are the manufacturer or brand owner of NAC - N-Acetylcysteine (Cysteplus) and believe any data on this page is incorrect (wrong dose, wrong ingredient, wrong price, missing certification, outdated status), you can request a correction.

We review every request, verify it against primär sources, and publish any change with a dated note in the version history above. Corrections from brand owners are treated the same as corrections from anyone else: verified before they move.

Request a correction →

Same shelf

Similar produkter

All Amino acid →

The next highest-scoring produkter in Amino acid, same scoring method, same rules.

$0.20

Lab-testatPublic analysintyg

Pris kontrollerat aug 2026 · bulksupplements.com

BulkSupplements

N-Acetyl L-Cysteine (NAC) Powder

7.4

Amino acid

$0.13

Pris kontrollerat aug 2026 · bulksupplements.com

Jarrow Formulas

Jarrow Formulas N-A-C Sustain, 600 mg

7.4

Amino acid

$0.43

Pris kontrollerat aug 2026 · jarrowformulas.com

Same maker

Other produkter from Thorne HealthTech

Varumärke profile →

Curcumin Phytosome (formerly Meriva 500-SF)

7.8

Antioxidant

$0.60

Magnesium Bisglycinate

7.6

Mineral

67%

$1.30

Basic Nutrients 2/Day

7.4

Multi/greens

$1.07

$0.81

Lab-testatPublic analysintyg

$1.62