Longevity · Newsletter guide
The best longevity newsletters, free and paid
Longevity is the most hype-prone corner of health media, so this list deliberately mixes four kinds of voices and labels them: clinicians (Attia, Topol), working scientists (Sinclair, Kaeberlein), a neutral evidence reviewer (Examine), and one enthusiast (Johnson). Read only supplement vendors or only clinicians and you get a skewed view. Every entry below is free to receive; where a paid tier exists we say so.
We check each newsletter is still publishing, note whether it's free or paid, and link straight to the official signup. Free means the newsletter itself is free to receive; some link to articles behind the publisher's paywall, and we say so. We don't take payment for placement.
Ground Truths
Ground Truths is Eric Topol's Substack on what the new studies actually show: aging science, AI in medicine, and the biomedical stories that matter, from the Scripps cardiologist and author of Super Agers. It reads the primary literature and says plainly what holds up. Best for readers who want a clinician-scientist's honest read of the evidence.
- Best for
- Readers who want a clinician-scientist's read of new research
- Reading time
- ~7 minutes
- Topics
- Aging ScienceMedicineAI in MedicineEvidence
- Our take
- Best clinical voice on aging science
Examine
Examine's newsletter delivers free supplement and nutrition updates from the independent site that grades the evidence behind every supplement and diet claim, with no ads, no sponsors, and no supplement money. It is the neutral referee for everything else on this page. Best for readers who want claims checked before they act on them.
- Best for
- Readers who want longevity claims fact-checked
- Reading time
- ~4 minutes
- Topics
- SupplementsNutritionEvidenceResearch
- Our take
- Best neutral evidence check
The Big O
The Big O is Optispan's monthly note from Matt Kaeberlein, the aging researcher who ran the Dog Aging Project and now spends his newsletter and podcast separating real evidence from marketing. It covers Optispan's health pillars, the podcast, and the science with a skeptic's eye. Best for readers who want longevity without the hype.
- Best for
- Readers who want the skeptical, evidence-first read on longevity
- Reading time
- ~6 minutes
- Topics
- Aging ScienceHealthspanSkepticismResearch
- Our take
- Best skeptic's longevity letter
Longevity.Technology daily briefing
Longevity.Technology's free daily briefing covers the industry: funding rounds, clinical trials, biotech, and the companies turning aging science into products, plus events and data. It is the trade read for the longevity economy. Best for readers who follow the business and investment side of aging science.
- Best for
- Readers who follow the longevity industry and its money
- Reading time
- ~5 minutes
- Topics
- Longevity IndustryBiotechInvestmentClinical Trials
- Our take
- Best on the business of longevity
Don't Die
Don't Die is Bryan Johnson's Substack: dispatches from the Blueprint protocol, biomarker results, protocol changes, and the Don't Die movement, from the most public self-experiment in longevity. It is an enthusiast voice with commercial interests, and we label it as one. Best for readers who want the maximalist view and can weigh it accordingly.
- Best for
- Readers curious about the maximalist self-experiment, with eyes open
- Reading time
- ~5 minutes
- Audience
- 8,000+ subscribers
- Topics
- BiohackingProtocolsBiomarkersLongevity
- Our take
- Best window into the maximalist protocol
Outliyr
Outliyr is Nick Urban's twice-weekly biohacking newsletter: protocols and stacks you can try, product reviews, and the experiments behind them, from a site that has reviewed hundreds of products. It is an enthusiast voice with affiliate ties, stated plainly. Best for readers who want protocols to test rather than reviews to read.
- Best for
- Biohackers who want protocols and stacks to try
- Reading time
- ~5 minutes
- Audience
- 11,500+ readers
- Topics
- BiohackingProtocolsSupplementsExperiments
- Our take
- Best hands-on biohacking letter
Lifespan Insider
Lifespan Insider is David Sinclair's free e-newsletter on aging research, news, and updates about his work, from the Harvard geneticist behind the book Lifespan. As of August 2026 the signup page says the newsletter is launching in 2026, so sign up now and expect issues later. Read it for the science, and know he also co-founded longevity companies. Best for readers who want the optimist's view from inside the lab.
- Best for
- Readers who want the optimist's view from a working scientist
- Reading time
- ~5 minutes
- Topics
- Aging ResearchGeneticsLongevityScience
- Our take
- Best optimist's letter, once it launches
Hark’s List for longevity newsletters
Our pick in each lane, from the newsletters above. Updated August 2026.
| Best overall | Peter Attia's Weekly Newsletter |
|---|---|
| Best clinical voice | Ground Truths |
| Best research density | FoundMyFitness Newsletter |
| Best evidence check | Examine |
| Best skeptic | The Big O |
| Best on the industry | Longevity.Technology daily briefing |
Hark’s recommended bundles
Starter sets. Tap one and those newsletters are pre-picked when you build your newscast; you can add or drop any of them.
- Start with this bundle
Longevity essentials
- Start with this bundle
The science, both sides
- Start with this bundle
- Start with this bundle
Industry watch
Frequently asked
- Which longevity newsletter is the most rigorous?
- Ground Truths and Examine for evidence discipline, Optispan's The Big O for skepticism, FoundMyFitness for citation density.
- Which should a beginner start with?
- Attia's weekly for the framework, Huberman Lab (on our health guide) for daily habits, and Examine to check the claims the others make.
- Where do general health and retirement newsletters fit?
- Our health guide (hark.news/best-health-newsletters) covers everyday medicine and health policy; our retirement guide (hark.news/best-retirement-newsletters) covers the 50+ reader. This page is the aging-science layer between them.
- What's the best free longevity newsletter?
- Every entry here can be received free; the paid tiers (Attia's membership, FoundMyFitness's Science Digest, Examine+) add depth rather than access. Start with Attia's weekly for the framework and Examine to check claims.
- How can I listen to my longevity newsletters instead of reading them?
- Add the ones you like to your Hark newsletters. We deliver them to your private Hark address and turn them into a five-minute spoken briefing each morning, your personal inbox is never involved.
- How did you choose these?
- We include newsletters that are currently publishing, note whether each is free or paid, and link to the official signup. We don't take payment for placement, and we don't reproduce newsletter content; we point you to the source.
Last updated: August 2026