Brain fog. That flat, foggy feeling where words don't come as easily as they used to. Mental fatigue that no amount of coffee quite fixes. Mood that dips for no obvious reason. These are some of the most common things people raise with David Holden in consultations, and they're also exactly what Rewind was formulated to support.
Every cell in the body, brain cells included, relies on a molecule called NAD+ to produce energy and carry out basic repair work. NAD+ levels decline steadily with age, and Harvard geneticist David Sinclair's research has linked that decline to many of the changes people associate with getting older, memory and mental sharpness among them. Rewind is built around two compounds the body uses to replenish NAD+: NMN and NR.
Here's where it gets properly interesting. NMN spent close to three years fighting for its legal right to exist as a supplement at all. In 2022, US regulators pulled it from the market on a technicality, a pharmaceutical company's early drug patent filing meant it technically couldn't also be sold over the counter. It took a sustained industry campaign, and until September 2025, for that decision to be reversed. It's a genuinely good underdog story, and Xtralife founder Matt Bowden goes into it in more depth in his interview with David, well worth a watch for the fuller picture.
Rewind doesn't rely on NMN alone, each capsule is formulated half NMN, half a related molecule called NR (nicotinamide riboside). Exactly how each of these closely related molecules makes its way from the gut into specific tissues like the brain is still being actively mapped by researchers, a genuinely open question, with competing findings still being published. Rather than betting on one pathway being the right one, combining both is a sensible hedge across an area of science that hasn't fully settled yet.
Rewind is available directly through Xtralife. Use the HHC code at checkout for a discount as an HHC patient.
Brain fog, mental fatigue and mood swings that don't settle can have a lot of different roots, sometimes lifestyle and stress, sometimes something more specific, like a hormone imbalance, that's worth actually investigating rather than guessed at. If what you're feeling has been going on for a while, a consultation with David looks at the fuller picture: your biochemistry, your hormones, and how your body's actually coping day to day, rather than leaving you to work it out from a bottle alone.
David Holden, ND (NZ), MS (USA), Dip.Biochem (Aus) / Naturopathic Oncology / Nutritional Biochemistry / Biohacking Healing Coach / david@hhc.nz / 0274 837 188 (SMS preferred)
