Life Extension uses **NIAGEN**, the patented nicotinamide riboside form behind virtually every published human trial on NR. That's the gold standard for raising NAD+ levels — the coenzyme your cells rely on for energy production, DNA repair, and activating the sirtuin pathways linked to healthy aging. The form quality here is as good as it gets.

The issue is dose. At 100 mg per capsule with a one-capsule daily serving, you're getting well below the 250–1,000 mg range used in clinical research. Human studies show NR raises blood NAD+ levels in a dose-dependent manner, but the meaningful increases (50%+ above baseline) come at 300 mg and above. At 100 mg, you're at 40% of the minimum studied dose.

If you want to reach a clinically relevant intake, you'd need to take 3 capsules daily — which burns through the 30-capsule bottle in 10 days. Life Extension also makes a 300 mg version of this product, which gets you into the studied range in a single capsule.