California Gold Nutrition NMN Review 2026: 175 mg Dose, iHerb House Brand, and the Price-per-Milligram Math

What Is in the Capsule

Each capsule contains 175 mg of β-NMN at 98% purity. Other ingredients include organic gum acacia powder, microcrystalline cellulose, an HPMC veggie capsule shell, stearic acid, magnesium stearate, and silicon dioxide. This is more excipients than most competitor NMN products.

We took these details from the iHerb product page on October 17, 2026. The NMN is the only active ingredient. The excipient list is longer than what you will find in brands like DoNotAge (NMN and capsule shell only) or ProHealth (NMN with minimal fillers). The presence of magnesium stearate and stearic acid is standard in mass-market supplements as flow agents that help powder fill capsules evenly during high-speed manufacturing. Some buyers specifically avoid magnesium stearate, though no published evidence shows it affects NMN absorption or safety at supplement doses.

The 98% purity is lower than the 99% or 99.8% claimed by brands using Uthever NMN. CGN's product page does not name the NMN supplier. The page does state that the NMN is "GRAS-affirmed," meaning it has been evaluated as Generally Recognized As Safe under FDA standards. GRAS affirmation is a meaningful regulatory step that most standalone NMN supplements do not publicly cite.

CGN does not appear to use Uthever. The absence of a branded ingredient name means the NMN could come from any manufacturer that meets CGN's specification. For the buyer, this is neutral: what matters is the finished-product testing, not the supplier's brand, as long as the purity is verified.

The 175 mg Dose: Too Low, Just Right, or a Flexibility Play?

At 175 mg per capsule, CGN's dose is 30% below the lowest commonly studied dose of 250 mg and 65% below the most common trial dose of 500 mg. Whether this matters depends on what you are trying to do with NMN.

Published human trials have used 250 mg as the lowest effective dose. Okabe gave 250 mg daily for 12 weeks and saw higher blood NAD+ (Okabe et al., 2022). Yoshino used the same dose for 10 weeks and found improved muscle insulin sensitivity (Yoshino et al., 2021). No published trial has used 175 mg, so there is no direct evidence that this dose raises NAD+ or produces any measurable outcome.

That does not mean 175 mg does nothing. NMN is a precursor to NAD+, and the conversion is dose-dependent. Lower doses presumably produce smaller NAD+ increases. The question is whether a smaller increase is clinically meaningful, and no one has measured it at 175 mg.

CGN's product page frames this as a feature: "a balanced, everyday dose designed for consistent daily use." That phrasing positions the low dose as intentional rather than deficient. For buyers who want 250 or 500 mg, the math is straightforward: take two capsules (350 mg, close to 250–300 mg trial doses) or three (525 mg, close to the 500 mg standard). At three capsules, a 60-count bottle lasts 20 days and costs about $0.87 per 500 mg of NMN, still competitive.

The key question is not whether 175 mg is safe (it is), but whether it is a useful dose. For someone who does not know what dose they want and would like to start low, CGN's capsule lets you begin at 175 mg and titrate up. That flexibility has value, especially for first-time NMN users who are uncertain about tolerability.

What NMN Trials Actually Used: The Dose Map

Published human trials have tested NMN at 250, 300, 500, 600, 900, 1,000, and 1,200 mg daily. The most common dose is 250 mg. The broadest dose-response data comes from a 2023 study that tested 300, 600, and 900 mg and found NAD+ increases at all three levels, with higher doses producing larger effects.

Study	Daily dose	Duration	Key finding
Irie et al., 2020	100–500 mg (single dose)	Single day	Safe; NMN metabolites in blood
Yoshino et al., 2021	250 mg	10 weeks	Improved muscle insulin sensitivity
Okabe et al., 2022	250 mg	12 weeks	NAD+ increased; well tolerated
Yi et al., 2023	300, 600, 900 mg	60 days	Dose-dependent NAD+ increase; walking improved
Liao et al., 2021	300, 600, 1,200 mg	6 weeks	Ventilatory thresholds improved at 600+ mg
Fukamizu et al., 2022	up to 1,250 mg	4 weeks	No serious adverse events

Notice the gap: no trial tested anything below 250 mg. CGN's 175 mg sits in untested territory. None of that implies it is ineffective. NMN's conversion to NAD+ is a continuous function, not a binary switch, but it means any effect at 175 mg is extrapolated, not measured. For context, a 2026 head-to-head found NMN and NR raised NAD+ comparably (Christen et al., 2026), but both used doses above 175 mg.

Cost per 500 mg: The Real Comparison

At the labeled one-capsule serving, CGN is the cheapest NMN per capsule on the market. At three capsules to reach 500 mg, the cost is about $0.87 per 500 mg, competitive but no longer the cheapest. The 180-count bottle improves the economics.

Product	NMN per serving	Cost per 500 mg NMN	Capsules for 500 mg
CGN NMN (60ct, $17.33)	175 mg	about $0.87	3 (actually 525 mg)
CGN NMN (180ct, $46.01)	175 mg	about $0.77	3
Nutricost NMN	500 mg	about $0.57	1
DoNotAge NMN (powder)	500 mg	about $0.40	n/a (scoop)
YourHealthier NMN (our product)	500 mg	about $1.67	1
ProHealth NMN Pro 500	500 mg	about $1.50	1

CGN's 180-capsule bottle ($46.01) is the better value. At three capsules daily, it lasts 60 days and costs about $0.77 per 500 mg. That undercuts our own product and ProHealth but remains above Nutricost and DoNotAge powder. CGN's powder form (90g for $77.87, 300 mg per scoop) works out to about $0.43 per 500 mg, comparable to DoNotAge powder.

The headline "$17.33" price draws buyers in. The per-capsule cost is extraordinary. But the per-milligram comparison tells the real story, and CGN lands in the middle of the budget tier, not at the bottom. Reviews of the other products above are in our DoNotAge review, Nutricost review, and ProHealth review.

The iHerb Factor: What It Means to Be a House Brand

California Gold Nutrition is iHerb's owned or exclusive brand. That gives it prime placement on the world's largest online supplement retailer, explains the review volume, and means the product is not independently distributed. If you want CGN NMN, you buy from iHerb.

iHerb sells supplements to over 180 countries. Being the house brand means CGN products appear at the top of iHerb's search results, get featured in promotions, and benefit from iHerb's logistics and return infrastructure. The 32,000+ reviews on the NMN product reflect this distribution power more than anything else. No standalone brand can match that. Platform math, not product quality.

The distinction matters: the reviews fake. iHerb's review system requires a purchase, which makes its reviews more reliable than platforms that accept unverified feedback. But the sheer scale of reviews is a function of distribution, not a reflection of quality differences between CGN and a brand with 200 reviews.

The trade-off is independence. CGN NMN is not available on Amazon, the brand's own website, or other retailers. If iHerb is unavailable in your country or you prefer to shop elsewhere, CGN is not an option. That single-retailer dependency is unusual in the NMN market, where most brands sell through multiple channels.

32,000 Reviews: What the Volume Actually Tells You

CGN NMN has more reviews than every other NMN product combined. Most reviews are short, positive, and mention energy or general wellbeing. The volume reflects iHerb's distribution reach and purchase-verified review system, not a quality difference versus products with fewer reviews.

We scanned the first several pages of reviews on iHerb. The most common positive themes are perceived energy improvement, easy-to-swallow capsules, and price satisfaction. The most common concerns are the low dose per capsule and the desire for a higher-dose option.

Several international reviewers noted they chose CGN specifically because it was the cheapest NMN available on iHerb with a meaningful review count. That pattern suggests the product serves as a high-volume entry point: buyers who are trying NMN for the first time and do not want to spend $50 to $80 before knowing if they notice anything.

No NMN supplement, including CGN, has demonstrated anti-aging effects in large human trials. A 2021 review of NAD+ precursors described the field as having clear biological activity but gaps in effectiveness data (Palmer et al., 2021). Positive reviews from 32,000 buyers are encouraging but do not substitute for controlled evidence.

GRAS-Affirmed Status: What It Means and What It Does Not

CGN's NMN is labeled "GRAS-affirmed." GRAS stands for Generally Recognized As Safe and is an FDA regulatory pathway. It means the ingredient has been evaluated for safety by qualified experts. It does not mean the FDA has approved the product for treating any condition.

GRAS affirmation can come through FDA notification (where the agency reviews the evaluation and issues a "no questions" letter) or through a brand's own expert panel. CGN's page does not specify which pathway was used. Either way, having GRAS documentation is a higher bar than most NMN supplements clear. Many NMN products are sold as dietary supplements without any GRAS filing.

What GRAS does not do is guarantee purity or potency for any specific batch. It addresses the safety of the ingredient in general use, not the quality of each bottle. For batch-level quality assurance, the relevant documents are certificates of analysis. CGN's page states that the product is produced in an FDA-registered, third-party audited, cGMP-compliant facility, which is standard for iHerb house brands. We did not find a publicly linked, downloadable COA for a specific lot.

NMN's regulatory history is relevant here. The FDA temporarily excluded NMN from the dietary supplement definition in 2022 but reversed that position in September 2025. Our NMN FDA status timeline covers the details. CGN's GRAS label predates or coincides with the reversal and signals that the brand took the regulatory question seriously.

CGN NMN Powder: A Separate Product

CGN also sells NMN as an unflavored powder in 30g ($35.20) and 90g ($77.87) sizes, with a 300 mg scoop. The powder contains NMN plus microcrystalline cellulose and silicon dioxide. At $0.43 per 500 mg from the larger container, it competes with DoNotAge powder on price.

The powder's per-scoop dose of 300 mg is close to the 300 mg group in Yi et al.'s dose-response trial, which found NAD+ increases and improved walking distance (Yi et al., 2023). That makes the powder a better alignment with trial data than the 175 mg capsule at its labeled serving.

A 2026 study found that sublingual NMN produced the same blood NAD+ levels as swallowed NMN over one hour (Wakabayashi et al., 2026). So the delivery route does not appear to matter for absorption, but powder gives you flexible dosing that capsules cannot match.

The CGN NMN Flavonoid Complex ($28.31 for 60 capsules) adds apigenin from chamomile extract and dihydroquercetin from Dahurian larch, with a lower 150 mg NMN dose. That product targets buyers who want a polyphenol stack alongside NMN. We focus this review on the plain NMN capsule because it is the direct comparison against other single-ingredient NMN products.

Safety of NMN at Trial Doses

CGN's labeled dose of 175 mg is well within the tested safety range. NMN has been studied in humans up to 1,250 mg daily for four weeks without significant adverse events. A 2026 meta-analysis found oral NMN generally well tolerated.

The safety data for NMN supports doses far above CGN's label. The highest-dose safety study gave 1,250 mg daily for four weeks (Fukamizu et al., 2022). A 2026 meta-analysis across multiple trials found no pattern of adverse events from oral NMN supplementation (Yang et al., 2026). Taking two or three CGN capsules daily to reach 350 or 525 mg is well inside this range.

A broader review of 113 NAD-related studies described clear biological activity from NAD+ precursors but concluded that evidence for anti-aging or wellness outcomes remains inconclusive (Gallagher et al., 2026). That assessment applies to NMN at any dose from any brand.

People who are pregnant, breastfeeding, or taking prescription medication should talk to a doctor before starting NMN. Our NMN side effects guide lists commonly reported effects from published trials. Our NMN dosage guide covers how to choose between doses.

Shipping and Availability: The iHerb Logistics Advantage

Because CGN ships exclusively through iHerb, buyers in over 180 countries can order it with iHerb's logistics, tracked shipping, and return infrastructure. Most standalone NMN brands ship only from the US and charge premium international rates. This global accessibility is CGN's strongest advantage for buyers outside the US.

iHerb operates warehouses in the US, Asia, and Europe, which means shipping times and customs handling are generally faster and smoother than ordering from a brand's own US-based Shopify store. For a buyer in Japan, South Korea, or Europe, CGN NMN may arrive days faster and at lower shipping cost than ordering the same dose from ProHealth, Nutricost, or our own product.

This logistical advantage is invisible in a price table but real in practice. A product that costs $17.33 plus $5 in iHerb shipping to Singapore is a fundamentally different proposition than a $35 product plus $15 in brand-direct international shipping. The total cost of ownership, not just the bottle price, matters for international buyers. Our own international shipping details are on our NMN product page.

Excipients in CGN vs Clean-Label Competitors

CGN uses more excipients (gum acacia, microcrystalline cellulose, stearic acid, magnesium stearate, silicon dioxide) than most single-ingredient NMN competitors. These are standard in high-volume supplement manufacturing but matter to buyers who prioritize minimal ingredients.

For comparison, DoNotAge lists only NMN and the capsule shell. ProHealth lists NMN, rice flour, and a capsule shell. Nutricost lists NMN, rice flour, and gelatin capsule. CGN's list is longer because mass-production at iHerb's scale requires flow agents (magnesium stearate, silicon dioxide) and bulking agents (microcrystalline cellulose) to keep capsule fills consistent across millions of units.

Magnesium stearate is the most frequently questioned excipient in the supplement industry. Studies on its effects are mostly in vitro and use concentrations far above what a single capsule delivers. A widely cited concern that magnesium stearate suppresses immune function comes from a 1990 study that tested stearic acid on T cells in a laboratory dish, not in humans taking supplements. The National Institutes of Health lists magnesium stearate as an inactive ingredient that is generally regarded as safe.

For buyers who actively avoid magnesium stearate, DoNotAge or a powder-based NMN product is a cleaner option. For most buyers, the excipients in CGN are a non-issue functionally, even if the longer ingredient list looks less appealing on paper. The NMN itself is what matters.

One detail worth noting: CGN lists "organic gum acacia powder" as the first other ingredient. Gum acacia (also called gum arabic) is a plant-derived fiber used as a binder. The organic certification on the gum acacia specifically, not on the NMN, is a niche quality signal that few NMN products include.

Who CGN NMN Fits

CGN NMN fits the iHerb shopper who wants an affordable entry point into NMN, values the GRAS-affirmed status, and is comfortable adjusting their capsule count to reach a trial-relevant dose. It does not fit someone who wants a one-capsule 500 mg dose or who shops outside iHerb.

The iHerb loyalist. If iHerb is already your supplement retailer, CGN NMN is the most accessible and cheapest NMN option on the platform. The purchase and return experience is handled by iHerb, which has strong customer service infrastructure.

The price-first buyer. At $17.33 for a bottle, the entry price is the lowest in the NMN market from a brand with stated purity and cGMP manufacturing. If budget is the constraint, CGN removes the financial barrier.

The 250 mg user. Someone who wants the lowest trial-tested dose can take one to two capsules daily (175 or 350 mg). At one capsule, a 60-count bottle lasts two months for $8.67 a month. That is genuinely cheap.

The 500 mg user who counts pills. If you want 500 mg daily and dislike taking three capsules, a single 500 mg capsule from Nutricost, ProHealth, or our own product is simpler. Three CGN capsules give you 525 mg, close enough, but more swallowing.

The documentation-focused buyer. If downloadable, lot-specific COAs are your minimum standard, check whether CGN provides them on request. The product page references third-party auditing and cGMP compliance but does not link to a public COA. Our NMN COA checklist covers what to ask for.

Our Verdict on CGN NMN

The cheapest entry ticket into NMN, from a brand backed by the world's largest supplement retailer. It works. The dose is low.

Take two or three capsules to reach a trial-relevant dose, and the per-milligram math is competitive but no longer the cheapest. If you already shop on iHerb and want to try NMN without committing $50, this is where to start. If you know you want 500 mg per serving in a single capsule, look elsewhere.

What We Did Not Review

We have not ordered the product, obtained a batch certificate, or evaluated the Flavonoid Complex or powder variants. This review covers the plain NMN 175 mg capsule from the iHerb listing and label data available in October 2026.

YourHealthier sells an NMN product, listed as ours in the price table above. Neither California Gold Nutrition nor iHerb reviewed or approved this article.

CGN vs Other Budget NMN: Side by Side

In the budget NMN tier, CGN competes primarily with Nutricost (capsules) and DoNotAge (powder). Each wins on a different criterion. CGN has the lowest entry price and GRAS status. Nutricost has the lowest cost per 500 mg capsule. DoNotAge has the lowest cost per gram in powder with named lab testing.

Feature	CGN NMN	Nutricost NMN	DoNotAge NMN Powder
NMN per serving	175 mg	500 mg	500 mg
Cost per 500 mg	~$0.77–$0.87	~$0.57	~$0.40
Format	Capsule	Capsule	Powder
Capsules for 500 mg	3	1	n/a
Purity claimed	98% GRAS	98%	99.8%
Named testing lab	Not specified	Not specified	Eurofins Scientific
Where to buy	iHerb only	Amazon, brand site	donotage.org
Review count	32,000+	~3,000	~500 (Trustpilot)

If your priority is entry price, CGN wins at $17.33 a bottle. If it is cost per milligram in capsule form, Nutricost wins. If it is cost per milligram in any form plus named lab documentation, DoNotAge powder wins. The "best budget NMN" depends on which of those you value most. Reviews of each are on our blog: DoNotAge review, Nutricost review, and our best NMN supplements guide compares all brands.

California Gold Nutrition NMN FAQ

Common questions based on the iHerb product page and the evidence above.

How much NMN is in each CGN capsule?

175 mg of β-NMN per veggie capsule. To reach 500 mg, take three capsules (525 mg total).

Why is the dose only 175 mg?

CGN positions it as a "balanced, everyday dose." The practical effect is a low per-capsule price and flexible dosing. Most trials used 250 to 500 mg.

Is CGN NMN third-party tested?

The product is made in a third-party audited, cGMP-compliant facility. A downloadable lot-specific COA was not visible on the product page. Contact iHerb customer service for documentation.

What does GRAS-affirmed mean?

The NMN ingredient has been evaluated as Generally Recognized As Safe by qualified experts under FDA standards. It does not mean the product is FDA-approved.

Can I buy CGN NMN outside iHerb?

No. California Gold Nutrition is an iHerb-exclusive brand. The product is not available on Amazon or other retailers.

How does CGN compare to Nutricost NMN?

Nutricost offers 500 mg per capsule at about $0.57 per serving. CGN offers 175 mg at $0.29 per capsule but $0.87 per 500 mg. Nutricost is cheaper per milligram and requires fewer capsules. CGN has GRAS-affirmed status.

Is 175 mg enough to raise NAD+?

No published trial has tested 175 mg. The lowest tested dose with measured NAD+ increases is 250 mg. Whether 175 mg produces a meaningful effect is unknown.

Where can I compare other NMN products?

See our best NMN supplements guide, What Is NMN?, and our own capsule on the YourHealthier NMN product page.