Injectable NAD+ vs. pills: what the evidence actually shows

What did @estellelatoya actually say?

She made a straightforward case for injecting NAD+ over taking it orally. Her core argument: pills lose potency in digestion before reaching the bloodstream, while injections deliver NAD+ directly to cells, producing faster and longer-lasting effects. She also shared personal results, including better gym recovery, increased energy, and reduced sugar cravings after a few months of injectable NAD+ from IVRX, a service she's affiliated with.

To her credit, she kept the mechanistic explanation simple and mostly stuck to her own experience rather than overpromising clinical outcomes. She did not claim NAD+ treats or cures anything. That said, some of her framing around bioavailability and cellular delivery oversimplifies what the research actually shows, and a few claims land somewhere between plausible and unverifiable.

Does the science back this up?

The bioavailability argument has real legs, but it's more complicated than she suggests. NAD+ taken orally does get broken down in the gut, largely into nicotinamide and other precursors, before entering circulation. However, injectable NAD+ also does not travel intact to cells as cleanly as the video implies.

NAD+ itself is a large molecule. Research by Camacho-Pereira et al. (2016, Science) showed that extracellular NAD+ can signal through cell surface receptors, but intracellular NAD+ replenishment in most tissues relies on biosynthetic pathways, not direct import. A 2023 review by Shade in Nutrients noted that while IV and subcutaneous NAD+ do raise plasma NAD+ levels faster than oral precursors like NMN or NR, there's limited human trial data directly comparing clinical outcomes between routes. The energy and recovery effects she describes are biologically plausible, but the idea that injecting NAD+ sends it straight into your cells in a usable form is an oversimplification that most researchers would push back on.

What did they get wrong (or right)?

She got the general bioavailability concept right. Oral NAD+ does face significant first-pass metabolism. That part is not controversial. Where she misses the mark is the claim that injections deliver NAD+ "directly into your bloodstream and your cells." Plasma delivery and intracellular delivery are not the same thing, and she conflates them.

The claim that injectable NAD+ produces "longer lasting benefits" for energy metabolism and anti-aging is also not well supported by controlled human trials. Most of the mechanistic work on NAD+ and aging comes from preclinical rodent studies. The few human trials, such as Yoshino et al. (2021, Science) on NMN supplementation in postmenopausal women, show metabolic improvements with oral precursors, which complicates the narrative that injection is clearly superior. Her personal experiences, reduced cravings, better gym recovery, are real to her, but they're anecdotes in the context of an undisclosed affiliate relationship with the brand she recommends.

What should you actually know?

NAD+ is a genuinely interesting area of longevity research, but it's not a proven anti-aging treatment in humans. The affiliate disclosure here matters. She mentions IVRX and links to it in her bio, which means her enthusiasm is financially entangled with her recommendation, even if she personally uses the product.

Injectable NAD+ is also not without downsides. IV infusions in particular are associated with side effects like nausea, flushing, chest tightness, and muscle cramping, particularly at higher doses or faster infusion rates. Subcutaneous injections are generally milder but still carry infection risk if not administered correctly. If you're considering injectable NAD+, this is a conversation to have with a licensed clinician, not a TikTok comment section.

• No large-scale randomized controlled trial has compared injectable NAD+ to oral precursors on clinical outcomes in healthy adults.
• The science on NAD+ and longevity is promising but largely preclinical. Human data is limited and early-stage.
• Compounded injectable NAD+ products are not FDA-approved drugs and vary in quality by compounding pharmacy.