NOW NAC Review 2026: 600 mg, Selenium, Testing and Value

NOW NAC 600 mg is one of the strongest value-oriented NAC products in the current market. It uses the common 600 mg unit dose, is sold in several bottle sizes, and was included in ConsumerLab's 2026 independent NAC testing.

The one formulation detail buyers should notice: the current U.S. product also includes 25 mcg selenium per capsule.

NOW NAC 600 mg at a glance

NAC per capsule	600 mg
Added selenium	25 mcg per capsule
Current U.S. sizes	30, 100, 120, 250 capsules
Current regular prices	$9.99, $21.99, $23.99, $47.99
Independent 2026 test	Included in ConsumerLab NAC testing
Best for	600 mg dose, broad availability and larger bottle options

Current formula

The current U.S. Supplement Facts panel lists 600 mg NAC and 25 mcg selenium per capsule. Other ingredients include hypromellose, stearic acid, citric acid and microcrystalline cellulose.

View the current NOW NAC 600 mg label.

Sizes and price

NOW currently lists 30-, 100-, 120- and 250-capsule sizes. At our October 2026 check, regular prices were $9.99, $21.99, $23.99 and $47.99 respectively; promotional sale prices were lower on several sizes.

That makes NOW particularly useful for buyers who want either a small trial bottle or a large-count long-term bottle.

Independent testing

ConsumerLab included both NOW NAC 600 mg and NOW NAC 1,000 mg in its April 2026 independent review. Its public report says every tested NAC product contained its labeled amount within an acceptable margin.

This is a major reason NOW performs well: ordinary pricing plus independent market testing.

The selenium question

If you use two capsules daily, the current U.S. formula contributes 50 mcg selenium/day. That can be reasonable, but it still counts toward total intake.

If your multivitamin or another supplement already contains selenium, check the combined amount rather than assuming the added nutrient is irrelevant.

U.S. vs Canada

NOW Canada currently lists a 600 mg NAC product with 25 mcg selenium under NPN 80128694. The Canadian directions differ from the U.S. label, which is a good reminder not to copy dosing instructions across markets.

What NOW gets right

• common 600 mg unit dose;
• multiple bottle sizes;
• independent 2026 testing;
• broad U.S. and Canadian availability;
• strong value in larger bottles.

What to watch

• Added selenium: useful for some buyers, unnecessary for others.
• Market-specific labels: directions can differ by country.
• Do not pay extra for “free form” language: NAC is inherently free form.

NOW NAC vs Thorne NAC

	NOW NAC	Thorne NAC
NAC/capsule	600 mg	500 mg
Added nutrient	25 mcg selenium	None
ConsumerLab 2026	Included	Included
Price position	Value / mid-range	Premium

Compare NAC brands before you buy

• Thorne NAC review
• NOW NAC review
• Pure Encapsulations NAC review
• Life Extension NAC review
• Nutricost NAC review
• Solgar NAC review

For the full comparison, see Best NAC Supplements 2026. For retailer and marketplace guidance, see where to buy NAC.

Cost normalized to NAC amount

At the current regular price, the 100-capsule bottle works out to about $0.22 per 600 mg (~$0.37/g). The 250-capsule bottle is more efficient at roughly $0.19 per 600 mg (~$0.32/g). Always recalculate when promotions change.

Bottom line

NOW NAC 600 mg is one of the easiest products to defend on dose, availability, testing and value. The main caveat is the added selenium. If that fits your stack, NOW is a strong standalone NAC choice.