This week the newsletter answers three of the questions we keep getting in reply. Today's is the biggest of them. Should you be on a GLP-1?
Short honest answer, for the majority of Longevity Daily readers, no. The drug class was designed for type 2 diabetes and adapted for obesity. If you are metabolically healthy with a body composition already close to where you want it, there is no compelling case to be on one for longevity. The lifestyle levers we have covered every week here are cheaper, safer, and still winning on absolute-risk arithmetic for anyone in that population.
The reason we are running the piece at all is that the drug class has quietly become the most important pharmacological longevity intervention of the decade for a specific population. Adults with obesity plus existing cardiovascular disease. Adults with heart failure with preserved ejection fraction. Adults with type 2 diabetes and chronic kidney disease. Three separate landmark trials in the last two years have moved us on this. Pharma is usually our last resort. For these patients, it isn't.
The evidence
The flagship trial is SELECT, published in the New England Journal of Medicine in November 2023 by A. Michael Lincoff and colleagues. 17,604 adults with existing cardiovascular disease and overweight or obesity, and specifically without diabetes, randomised to semaglutide 2.4mg weekly or placebo. Median follow-up close to 3 years. The primary composite of cardiovascular death, non-fatal heart attack, and non-fatal stroke was 20 percent lower in the semaglutide arm. Hazard ratio 0.80, 95 percent confidence interval 0.72 to 0.90. The trial was designed to detect a cardiovascular benefit independent of weight loss, and it did.
The second is STEP-HFpEF, published in the NEJM in August 2023 by Mikhail Kosiborod and colleagues. 529 adults with heart failure with preserved ejection fraction and obesity, randomised to semaglutide 2.4mg or placebo for 52 weeks. Heart failure symptoms improved. 6-minute walk distance improved. Weight came down. Inflammatory marker CRP dropped 43 percent versus 7 percent in placebo. And notably, serious adverse events were lower in the semaglutide group than in the placebo group, 13 versus 27 percent. This is the trial that pushed most cardiologists in the HFpEF space to add GLP-1 to their playbook.
The third is FLOW, published in NEJM in May 2024 by Vlado Perkovic and colleagues. 3,533 adults with type 2 diabetes and chronic kidney disease, randomised to semaglutide 1mg weekly or placebo. The trial was stopped early at a prespecified interim analysis because the drug was working too well to keep the placebo arm going. Kidney outcomes were 24 percent lower. Cardiovascular events 18 percent lower. All-cause mortality 20 percent lower. Every hard endpoint moved in the same direction.
Weight loss is the headline everyone knows. The trials are measuring something bigger. Underneath the scale number, a whole panel of markers moves in the right direction:
Triglycerides down
Cholesterol ratios improving
ApoB down
CRP inflammation down (STEP-HFpEF: 43 percent drop)
Visceral fat down; SELECT participants lost close to 8 cm of waist over 4 years
All-cause mortality down (FLOW: 20 percent reduction)
That is the actual game. The scale number is the byproduct.
And underneath all of it, patients said their days felt bigger. Which, in the end, is the point of every number above.
The card shows the three headline numbers: 20% fewer CV events in SELECT, 24% fewer kidney outcomes in FLOW, 43% CRP inflammation drop in STEP-HFpEF.
Where the anti-pharma default breaks
Longevity Daily runs on a rule we have been consistent on for months. Default naturopathic-first for sleep, mild-to-moderate anxiety, cardiovascular prevention, T2D and metabolic health, joint pain, cognitive function, hormone support, gut health. Lifestyle levers are our answer to almost every question. We name over-prescription patterns and we translate relative risk into absolute risk. That is not changing.
What has changed is that a specific pharmacological class has produced three independent landmark trials in obese with cardiovascular disease, HFpEF, and T2DM plus CKD populations, showing meaningful all-cause mortality reduction with acceptable adverse event profiles. Under our own hierarchy of trust, that is convergent, high-quality peer-reviewed evidence we have to take seriously. For the people the trials enrolled, the drug is now a defensible longevity intervention. For the people the trials did not enroll, it is not.
What this means for you
If you have a BMI over 30 plus established cardiovascular disease, prior heart attack, prior stroke, or documented HFpEF, this is a conversation to have with your cardiologist. The SELECT population is exactly that group and the absolute risk reduction is meaningful. If you have type 2 diabetes and any degree of chronic kidney disease, this is a conversation to have with your endocrinologist and your nephrologist. The FLOW arithmetic is compelling and the drug now has a hard mortality benefit in your specific group.
If you are metabolically healthy with a BMI under 30, no diabetes, and no established cardiovascular disease, the trials did not enroll people like you and the extrapolation is not defensible. The wellness internet is currently marketing GLP-1 as a general longevity drug for the worried well, and that is not what the evidence supports. That is what happens when a real signal in a defined population gets flattened into a marketing pitch for a much broader one.
If a GP or a compounding pharmacy has offered you a GLP-1 for weight loss without a specific medical indication, treat it the same way you would treat any pharma offer. Ask about the trial evidence in your specific population. Ask about the number needed to treat and the number needed to harm. Ask what happens when you stop the drug. And ask what the honest lifestyle equivalent looks like before you agree to the injection.
Where are you actually falling short? The Healthspan Assessment is a 5-minute quiz that scores you across the levers we cover in this newsletter, and tells you which one to work on first. Free, no blood draw.
Wednesday preview
Wednesday takes the second reader question of the week. Should you be vegan or plant-based after 50? The plant-forward literature is real, and so is the sarcopenia literature that says protein needs rise, not fall, as you age. Wednesday walks both sides, and gives our honest answer.
Reply and tell us a question you would have asked in this series. We are building a collection for the next round.
Until Wednesday.
Longevity Daily · The Building Decades
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P.S. Forward this to the friend or family member who has been asking about Ozempic. It is the honest read they are unlikely to get from a prescriber.