"I Didn't Stop Hiking Because I Got Old. I Stopped Because Getting Up The Next Morning Cost Me The Whole Day."

A 68-year-old on the arithmetic nobody warns you about - and the single number that made her look at this again after six years of writing it off.

I stopped hiking at 64.

Not because I got old. Because I did the eight-mile loop on a Saturday, came home perfectly fine, and then spent the whole of Sunday in a chair.

So the next month I did six.

Then six, and cancelled the Sunday plans in advance.

Then I stopped putting it in the calendar at all - because I'd stopped being willing to spend two days on one.

That took eleven months. I did not notice a single step of it.

It never once felt like a decision. Every subtraction was sensible on its own. That's exactly what makes it invisible.

You start arranging the week around what your body will allow. One thing per day. Never two days running. You decline the evening because there was already a daytime, and you give a reason that isn't the reason — because the honest version, I can't afford tomorrow, sounds far worse out loud than it feels.

I want to be precise about this, because every leaflet aimed at women my age gets it wrong.

I was not in pain. I was not frail. I could still have done the eight miles that Saturday and the Saturday after.

I simply couldn't pay for it any more.

What shrank wasn't what I could do. It was how far from my own front door I was still willing to plan.

Two reasons. I stand by both.

The first is that I was already trying to take fewer pills, not more. There's a drawer in my kitchen and I have spent years getting it emptier. My GP and I have had that conversation twice. Adding something back needed a better reason than an advertisement.

The second is that this industry has a habit of finding women my age and lying to them. A memory supplement was taken to court over its claims. There are "trials" that start at $19.95 and quietly become $79.95 a month with a cancellation number nobody answers. A friend of mine calls the whole shelf expensive urine, and most weeks she's right.

I'd bought an NMN capsule years ago on somebody's recommendation. Two months. Nothing. Threw it out.

It came from a woman in my walking group. She's 74, she does the full loop while the rest of us cut the corner, and she is not a person who forwards things.

She sent me one finding. It wasn't a flattering one.

A trial of 140 healthy adults, aged 40 to 60. Three doses, eight weeks, blood measured in a laboratory. The 300 mg group's NAD+ went up 51%. The 1,000 mg group's went up 142%.

And the 100 mg group was no different from placebo. At every single measurement. Not slightly weaker. The same as nothing.

I went and found the bottle I'd thrown out.

It was 250 mg. Split across two capsules.

Six years. I had never once tested the thing I thought I'd tested. I'd tested a dose that was already known not to work, decided the category was nonsense, and shrunk my life by four miles while I was at it.

I'm not a scientist. I ran a school office for thirty-one years, which mostly means I know what a document looks like when somebody has actually signed it.

First: is there anything in it at all. An independent lab put fifteen NMN products through analysis and published the contents. The range ran from nothing to slightly over the label. Three of them had no detectable NMN whatsoever. That is the real scandal in this business and nobody advertising in it mentions it.

OMRE tests every batch twice. Once on the raw powder — right molecule, how pure. Once on the finished capsule — actives, heavy metals, bacteria, mould. Purity printed as a number, over 99%, rather than the words "high purity," which mean nothing at all. GMP, FDA-registered facility in the United States. Formulated by a physician.

I asked for the certificate. It came by email. One flaw, which I'd want told to me: you can't type your own lot number into their site and pull your own batch. It's on the page and sent on request. Further than most. Not perfect.

Second: the label. Two capsules. 500 mg NMN, 500 mg trans-resveratrol, 5 mg of a black pepper extract for absorption. Every amount printed, nothing hidden inside a blend. I took that paragraph to my doctor and I'd tell you to do the same — resveratrol thins the blood slightly, and it matters if you're on a thinner, or blood pressure medication, or anything for diabetes.

Third: the trap. They do run a subscription, and it's cheaper — but nothing pushes you into it. I bought a single bottle, once, and nothing renewed and there was nothing to cancel on a Sunday evening. After the stories I've heard, that mattered more than it probably should.

Reserve. The capacity to absorb a hard day and still be usable the next.

Morifuji ran 60 people on 250 mg for twelve weeks and missed the primary endpoint. What improved were secondary findings, walking time and sleep-related daytime dysfunction (GeroScience 2024;46:4671–88). Secondary means hypothesis, not conclusion.

But walking speed and daytime function are the measurable shadows of the process I keep typing that word for, and they moved at an adequate dose in people her age. A modest claim, and the only one here I can make without embarrassing myself.

One question left. Did the bottle hold the dose those trials used.

Most fail immediately. Under 300 mg, or buried in a blend, which is the same as not telling me. If I cannot see milligrams I cannot reason about a dose.

The one I settled on prints every amount. 500 mg NMN, 500 mg trans-resveratrol, 5 mg piperine. Purity published as a number, over 99 percent, not the phrase "high purity." Assayed twice per batch, raw material and finished capsule, for identity, potency, heavy metals and microbial contamination. GMP, FDA-registered, domestic.

The resveratrol is there on mechanism, not outcomes; the best human trial found nothing (Diabetes 2013;62:1186–95). And you cannot enter a lot number to pull that batch's certificate. Retrieval by lot is the standard I want and it is not there.

He came back six weeks later.

The evidence for feeling sharper is not there, and nobody can sell it to him honestly.

The evidence for recovery and walking speed is early and secondary, but it exists at a real dose. More than most of what gets forwarded to him.

And we would go through his medication list first, because resveratrol has antiplatelet activity.

Then he asked if I took it.

I do. 500 mg daily since spring. My impression is that the Monday after a weekend on call is easier than it was.

I am one unblinded person who wanted it to work. Worst study design there is, and I would refuse it from a colleague.

So the aggregate matters more than I do. Across the reviews: 549 mention energy, 141 clearer thinking, 91 deeper sleep.

Onset runs four weeks to three months against a thirty-day refund window. Mark day 25 and decide then. It refunds on an opened bottle, which is the only thing that makes thirty days usable.

Every trial above is in PubMed, and two argue against the product. Read Martens and Zhang first.

Then buy one bottle and give yourself what you would give any patient. A real dose, an honest timeline, and permission to conclude it did nothing.

I still type that word most weeks. I would like to keep typing it about other people.