NMN 250 mg vs 500 mg Compared

The direct answer

Choose a 250 mg product when a lower labeled amount, fewer capsules, or clearer 250 mg finished-product documentation is the priority. Choose a 500 mg product when you specifically want 500 mg in one labeled serving and the capsule count, price, and test record still make sense. The number alone does not determine product quality or clinical value.

For the products checked here, Just Glow provides 250 mg in one capsule and publishes a finished-lot result of 276 mg per capsule. ProHealth provides 500 mg in one capsule and publishes a finished-lot result of 513.21 mg per capsule. Those are the cleanest one-capsule comparisons. Double Wood, Nutricost, Renue By Science, and ROKIT show why the serving panel changes the answer: their labeled serving uses two capsules, and ROKIT's 500 mg front-label total combines two different active ingredients.

Per capsule and per serving are different fields

Just Glow and ProHealth use one-capsule servings, so their per-capsule and per-serving amounts match. Double Wood lists 125 mg per capsule but 250 mg per two-capsule serving. Nutricost and Renue By Science list 250 mg per capsule but 500 mg per two-capsule serving. A bottle with 60 capsules can therefore contain either 60 one-capsule servings or 30 two-capsule servings.

FDA's dietary supplement labeling guide says a Supplement Facts panel must list the serving size, servings per container, and quantities of dietary ingredients. For supplements, one serving is generally the maximum amount recommended on the label for consumption per eating occasion. That makes the panel's serving line the consistent comparison point, even when a shopper later discusses a different amount with a clinician.

ROKIT needs one additional step. Its two-capsule serving lists 250 mg of NMN and 250 mg of pterostilbene. The 500 mg combined total cannot be placed in the 500 mg NMN column. Our per-capsule versus per-serving guide works through these labels line by line.

Human trials do not settle 250 mg versus 500 mg

Several randomized studies have used 250 mg of NMN daily for 12 weeks. Okabe et al. enrolled 30 healthy adults and reported an increase in whole-blood NAD+ without obvious adverse effects during the study. Igarashi et al. administered 250 mg daily to older men for six or 12 weeks. Morifuji et al. enrolled 60 older adults and found no significant difference in the primary stepping-test outcome, while reporting differences in selected secondary outcomes.

A separate dose-ranging trial randomized 80 healthy middle-aged adults to placebo or 300, 600, or 900 mg daily for 60 days. It reported higher blood NAD measures in all NMN groups and no safety issue during that short protocol. It did not include a 250 mg arm, did not test 500 mg, and did not compare current retail products.

These studies answer narrow questions about defined materials, populations, endpoints, and durations. They do not show that a 500 mg retail serving is twice as effective as 250 mg, that every person should use either amount, or that a higher label amount produces a longer life. Dose labels in this guide describe products, not medical instructions.

Use one denominator for price

Bottle price and price per labeled serving can mislead when the products contain different NMN amounts. We also calculate a label-based price per 500 mg of NMN: bottle price divided by total labeled NMN in the bottle, then multiplied by 500 mg.

Just Glow

$0.58 per 250 mg serving; $1.17 per 500 mg of labeled NMN.

Double Wood

$1.63 per 250 mg serving; $3.26 per 500 mg of labeled NMN.

ProHealth

$1.43 per 500 mg serving and per 500 mg of labeled NMN.

Nutricost

$0.73 per 500 mg serving and per 500 mg of labeled NMN.

Normalized price is not a quality score. It does not include finished-product traceability, contaminant scope, capsule count, delivery format, shipping, or the value of another active ingredient. It simply prevents a 250 mg serving from looking directly equivalent to a 500 mg serving.

Documentation can matter more than the larger number

A label states what a product is supposed to provide. A finished-product potency report can show what one tested lot measured. ProHealth's public report names SKU PH583 and lot 2509142 and reports 513.21 mg per capsule. Just Glow's finished report identifies lot 10126 and reports 276 mg per capsule. Renue By Science reports 507.776 mg per two-capsule serving for lot 062827351.

Those results are lot-specific, not permanent guarantees for every bottle. Raw-material purity is a separate field. A 99% or 99.9% purity result for bulk NMN does not establish the milligrams in a finished capsule. Read our NMN purity verification guide and COA checklist before treating any test badge as a product result.

Which label fits your priority?

• 250 mg in one capsule with finished-lot potency: Just Glow UTHEVER NMN.
• 250 mg in two capsules with finished-lot potency: Double Wood NMN.
• 250 mg NMN plus 250 mg pterostilbene: ROKIT America, with raw-material rather than public finished-lot documentation.
• 500 mg in one capsule with finished-lot potency: ProHealth Longevity NMN Pro 500.
• 500 mg in two capsules at the lowest current price in this group: Nutricost NMN, with a testing statement rather than a public current lot result.
• 500 mg in a two-capsule liposomal format: Renue By Science LIPO NMN, with public finished-lot potency.

Our best NMN supplements comparison weighs these fields together rather than ranking by milligrams alone. The NMN product specs database keeps the full eight-product field set in one place.

Sources and product records

• FDA Dietary Supplement Labeling Guide: serving size and Supplement Facts.
• Okabe et al., 2022: 250 mg daily for 12 weeks, Igarashi et al., 2022: 250 mg daily, and Morifuji et al., 2024: 250 mg daily.
• Yi et al., 2023: 300, 600, and 900 mg daily for 60 days.
• Just Glow, Double Wood, and ROKIT America product records.
• ProHealth, Nutricost, and Renue By Science product records.