How Fight Aging! Distinguishes Longevity Therapies by Evidence Strength

Fight Aging! argues that the longevity industry's biggest communication problem is not hype about any single therapy, but the habit of grouping very different interventions under one label. In the site's own words, lumping approaches together is "a category error that is becoming common." The practical takeaway for readers: judge each therapy by its own evidence base — reliability of animal data, effect size, and human trial results — rather than by the fact that it appears in a longevity headline.

The core distinction the site draws

The site's editorial position, stated in its coverage of a broad geroscience review, is that a survey which places NAD+ upregulation and senolytics under one heading misleads readers. Its reasoning rests on three separate comparisons:

• Reliability of animal data. Senolytics to clear senescent cells are described as having "reliable and extensive animal data." NAD+ upregulation is described as having "unreliable animal data."
• Effect size. Senolytics show a "large effect size for reversal of age-related conditions." NAD+ upregulation shows a "small effect size."
• Human trial history. NAD+ upregulation has a "long history of failed human trials for a range of conditions." Senolytics have "mixed data from only a few early human trials."

The site also notes that these therapies "emerge from very different philosophies of development" — meaning the difference is not just in results but in how each field decides what counts as sufficient proof before moving forward.

Why "promising" and "proven" are not the same claim

Fight Aging! frames the disagreement as a spectrum rather than a binary. On one end is what it calls an "archly conservative viewpoint," which links academic caution ("this thing you are doing has not yet been proven beyond all doubt to work") to industry caution ("this thing you are doing has not yet been proven beyond all doubt to generate profit"). Both positions treat the question — can human aging be slowed or reversed as it can in laboratory species? — as an unfinished test.

The site's own position is that this caution is a choice with costs: "one doesn't win victories by refraining from participation." But it does not resolve that tension by treating all candidates as equally likely to succeed. Instead it separates two questions:

1. Is there a plausible mechanism and some supporting data? (Many lines of work pass this bar.)
2. How much additional healthy life can this actually provide in humans? (For most, still unknown.)

The site states that for many lines of work, "the only remaining question is how much additional life they can provide to members of our own species." That is a claim about magnitude, not about whether the approach works at all — and it is a much weaker claim than "proven."

A practical reading checklist

When you encounter a longevity therapy in the news, apply the same three dimensions the site uses:

A therapy can be genuinely promising on mechanism while still lacking the human evidence to support strong claims. The site's objection is to collapsing those two states into one.

What this means for following the longevity industry

Fight Aging! does not ask readers to dismiss the industry — it explicitly notes that "a great many other people, scientists, entrepreneurs, patients, and patient advocates, are less conservative," and that this is why the field exists. Its ask is narrower: keep the categories separate. A broad review that surveys "everything that might fall into the purview of the diverse longevity industry" is useful as a map, but not as a ranking. Treat each entry as its own evidence case, and check which of the three dimensions above it actually satisfies before treating it as comparable to a therapy with extensive, replicated animal data and large effect sizes.