Lamivudine
Lamivudine (3TC), nucleoside reverse transcriptase inhibitor
Written by Aaron CuhaReviewed Sep 2026
Also known as: 3TC, Epivir, Epivir-HBV
A thirty year old HIV and hepatitis B drug repurposed on the hypothesis that LINE-1 retrotransposons drive the sterile inflammation of ageing. The human ageing evidence is one 12 person open-label pilot in Alzheimer disease with no control group.
Overview
Roughly 40 percent of the human genome is retrotransposon sequence. Most of it is silenced, and the silencing appears to fail with age. The hypothesis behind lamivudine in geroscience is that derepressed LINE-1 elements copy themselves through a reverse transcriptase step, leaving cytoplasmic complementary DNA that the cGAS-STING sensor reads as a viral infection, which drives a type I interferon response and chronic sterile inflammation.
If that is right, a reverse transcriptase inhibitor should interrupt it, and lamivudine is the obvious candidate because it has been given to millions of people for decades.
Two 2019 papers built the case. A Nature paper showed LINE-1 becomes transcriptionally derepressed during cellular senescence and activates a type I interferon response through cytoplasmic LINE-1 complementary DNA, and reported that treating aged mice with lamivudine downregulated interferon activation and age-associated inflammation in several tissues. A Cell Metabolism paper reported that SIRT6-deficient mice, which are severely short lived, accumulate cytoplasmic LINE-1 complementary DNA, and that nucleoside reverse transcriptase inhibitors significantly improved their health and lifespan while completely rescuing the interferon response.
Both are real results. Neither is a lifespan result in normally ageing animals. The Nature paper measured inflammation markers in aged mice, not survival. The Cell Metabolism lifespan gain was in a knockout model of accelerated ageing, which is a different claim.
In humans there is one study. ART-AD was an open-label phase 2a pilot in 12 people with early Alzheimer disease taking 300 mg of lamivudine daily. It reported a favourable safety profile, stable cognitive measures, a reduction in cerebrospinal fluid GFAP and a rise in plasma amyloid beta 42 to 40 ratio. Twelve people, no placebo group, biomarker endpoints.
Mechanism of action
A cytidine analogue that is phosphorylated intracellularly to lamivudine triphosphate, which is incorporated by reverse transcriptase and terminates the growing DNA chain because it lacks a 3 prime hydroxyl group. In HIV and hepatitis B that stops viral replication. The geroscience application targets the reverse transcriptase encoded by LINE-1 elements instead, with the aim of preventing cytoplasmic LINE-1 complementary DNA from accumulating and triggering cGAS-STING and type I interferon signalling. The proposed benefit is therefore reduction of inflammaging rather than any direct effect on the cellular machinery of ageing.
Human evidence
Thirty years of use in HIV and hepatitis B, with a large and well-characterised safety record. For ageing, one 12 person open-label pilot with biomarker endpoints and no control group.
- Approved and used since the 1990s in HIV combination therapy and in chronic hepatitis B, so the human safety picture at these doses is unusually well known for a repurposing candidate.
- ART-AD, 12 participants, open label, 300 mg daily: cerebrospinal fluid GFAP fell (P = 0.03) and plasma amyloid beta 42 to 40 ratio rose (P = 0.009), with cognitive measures described as stable.
- No placebo group in ART-AD, so stable cognition over the study period cannot be attributed to the drug.
- No human study has measured LINE-1 activity, inflammaging markers, biological age, frailty or lifespan in a healthy ageing population on lamivudine.
What this does not tell you: A 12 person uncontrolled pilot with surrogate endpoints is a feasibility study, and the authors present it as one. Stability of cognition in early Alzheimer disease over a short window is not a treatment signal without a comparator. The separate and practical problem is that the long human safety record comes from populations under specialist monitoring for the infection being treated, and a person taking lamivudine for ageing is outside that structure, including the risk of a severe hepatitis B flare on stopping the drug if they carry the virus unknowingly.
Reading the research record
There are two separate evidence questions about any repurposed drug and they have different answers. The first is whether the drug does what it was licensed to do, which here is settled by randomised trials with hard clinical endpoints. The second is whether it slows ageing in humans, which no trial has tested. The strength of the first answer says nothing about the second. A reader who takes the licensed indication as partial proof of the ageing claim has made the central error of this field.
The LINE-1 hypothesis is one of the more elegant ideas in current ageing biology and it has two independent 2019 papers behind it in Nature and Cell Metabolism. It is worth being precise about what those papers did and did not show. The Nature paper gave lamivudine to aged mice and measured interferon activation and tissue inflammation, and reported those falling. It did not run a lifespan experiment. The Cell Metabolism paper did report improved lifespan on nucleoside reverse transcriptase inhibitors, in SIRT6 knockout mice, which are a model of dramatically accelerated ageing rather than normal ageing. Extending the life of a short-lived mutant is a weaker claim than extending the life of a normal animal, and the two are routinely reported as if they were the same.
The Nature paper also carries a published author correction. That is a normal part of the record and not a retraction, and it is listed here because a reader checking the citation will see it and should know what it is.
There is no mouse lifespan study of lamivudine in normally ageing wild-type animals, which is the obvious experiment and its absence is the honest headline for this compound.
The evidence, charted
Fig. 1 · evidence composition
2of 5 citations (40%) are in people
Counted from the citation list on this page. The Human count is the same number shown in the badge at the top. Both understate any literature larger than the sources we cite.
Fig. 2 · evidence over time
Evidence spans 4 distinct years, 2019 to 2025, counted from the citation list on this page.
Fig. 3 · legal status at a glance
US
Approved
UK
Approved
AU
Approved
CA
Approved
Approved in all four jurisdictions shown. A jurisdiction's classification is a regulatory fact, not a verdict on the science; see Legal status below for the full text and any notes.
Fig. 4 · dose response
No human dose response curve exists
We draw this figure where the data supports it. For this compound in humans it does not, so the panel stays empty rather than borrowing an animal curve and implying it transfers.
Key studies & citations
- Animal2019
L1 drives IFN in senescent cells and promotes age-associated inflammation
The founding paper. LINE-1 elements become transcriptionally derepressed during cellular senescence and activate a type I interferon response, triggered by cytoplasmic LINE-1 complementary DNA and blocked by LINE-1 reverse transcriptase inhibitors. Treating aged mice with lamivudine downregulated interferon activation and age-associated inflammation in several tissues. Inflammation endpoints, not survival. The paper carries a published author correction in Nature in 2019, which is a correction and not a retraction.
Nature - Animal2019
LINE1 Derepression in Aged Wild-Type and SIRT6-Deficient Mice Drives Inflammation
The lifespan-shaped result, and it is in a progeroid model. SIRT6-deficient mice, which are severely short lived, accumulate cytoplasmic LINE-1 complementary DNA that triggers a type I interferon response via cGAS. Nucleoside reverse transcriptase inhibitors significantly improved the health and lifespan of these knockout mice and completely rescued the interferon response. The same paper reports elevated LINE-1 transcription, cytoplasmic complementary DNA and type I interferon in normally aged wild-type mice, without a lifespan experiment in those animals.
Cell Metabolism - Human2025
A Phase IIa clinical trial to evaluate the effects of anti-retroviral therapy in Alzheimer's disease (ART-AD)
The only human study in this line of work. Open label, no control group, 12 participants with early Alzheimer disease on 300 mg of lamivudine daily. Reported a favourable safety profile, stable cognitive measures, a reduction in cerebrospinal fluid GFAP (P = 0.03) suggesting reduced neuroinflammation, and an elevation in plasma amyloid beta 42 to 40 ratio (P = 0.009). The authors state the results warrant a larger placebo-controlled trial. One author discloses a scientific advisory role with a retrotransposon-focused company.
npj Dementia - Human2023
Pilot Study to Investigate the Safety and Feasibility of AntiRetroviral Therapy for Alzheimer's Disease
The ART-AD registration, listed as completed with an actual enrolment of 12, running from February 2021 to November 2023. The registry record confirms the pilot scale and the absence of a randomised comparator.
ClinicalTrials.gov - Animal2022
Lamivudine, a reverse transcriptase inhibitor, rescues cognitive deficits in a mouse model of down syndrome
An independent line of rodent evidence for the same mechanism in a different model, reporting rescue of cognitive deficits in a Down syndrome mouse model. Useful as replication of a mechanism in animals, and not evidence about ageing in people.
Journal of Cellular and Molecular Medicine
What users report
Self-reported experiences, not evidence. Nothing below was measured under controlled conditions, and reports like these cannot separate a real effect from placebo, from the training or diet change that accompanied it, or from what the product actually contained. They are here because knowing what people describe, including what goes wrong, is worth reading alongside the studies.
- Generally described as easy to tolerate, which is consistent with the clinical record, with headache, nausea and fatigue the most common early complaints.
- Longevity users typically take the hepatitis B dose or the HIV dose without knowing which the mouse work corresponds to, because no human dose-finding for this indication exists.
- The hepatitis B flare risk on stopping is under-discussed in longevity communities relative to how serious it is.
Sources: Longevity forums and clinic write-ups. Uncontrolled self-report, useful for what to watch for, not evidence of effect.
Frequently asked questions
Does lamivudine slow ageing?
There is no human evidence that it does. In aged mice it reduced interferon activation and age-associated inflammation in several tissues, and in SIRT6 knockout mice a reverse transcriptase inhibitor improved health and lifespan. No lifespan study exists in normally ageing mice, and the only human study is a 12 person uncontrolled pilot in Alzheimer disease.
What is the LINE-1 hypothesis?
LINE-1 retrotransposons make up a large share of the genome and are normally silenced. With age that silencing fails, and the reverse transcriptase step leaves DNA copies in the cytoplasm, where the cGAS sensor reads them as viral and triggers a type I interferon response. That response is proposed as a driver of the chronic sterile inflammation of ageing, and a reverse transcriptase inhibitor is the obvious way to test it.
What did the Alzheimer trial find?
ART-AD gave 300 mg of lamivudine daily to 12 people with early Alzheimer disease, open label with no placebo group. Cerebrospinal fluid GFAP fell and the plasma amyloid beta 42 to 40 ratio rose, both statistically significant, and cognitive measures were described as stable. With 12 people and no comparator these are hypothesis-generating biomarker results, which is how the authors present them.
Is it safe to take long term?
It has a long safety record in the populations it is licensed for, which is the strongest safety argument any compound on this page can make. The specific hazard for off-label ageing use is hepatitis B: someone with undiagnosed chronic hepatitis B who starts and then stops lamivudine can have a severe acute exacerbation, and that is exactly the person least likely to be under monitoring.
Is this the same idea as senolytics?
It is adjacent. Senescent cells are where the LINE-1 derepression and interferon response were characterised, so both approaches target the inflammatory output of senescence. Senolytics try to remove the cells; lamivudine tries to silence one specific signal they emit.