Low-dose naltrexone (LDN)

There is no human trial of LDN with a longevity or healthspan endpoint. The only lifespan evidence is invertebrate: a 2024 iScience study reported a 17.6 percent median lifespan extension and improved mobility in C. elegans at 2.5 micromolar via SKN-1 (the worm NRF2 orthologue), with no benefit at high dose. That is a worm result, not a mammalian or human one. In humans the best-developed dataset is fibromyalgia pain, where a 2025 systematic review and meta-analysis of five RCTs found a significant reduction in pain scores but small samples and limited robustness. For long COVID a 2025 systematic review found zero RCTs, only four observational pre-post studies (n=155), with low certainty of evidence. A 2026 narrative review in Advances in Therapy covering 105 studies including 15 RCTs concluded that early positive uncontrolled findings were rarely replicated in placebo-controlled trials and that the literature is dominated by case reports and small feasibility studies prone to publication bias. What the evidence does NOT show: any effect on ageing biomarkers, biological age, mortality, or any healthspan outcome in humans. Anyone presenting LDN as a longevity intervention is extrapolating from a worm study and an anti-inflammatory mechanism story.

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Common questions

What is Low-dose naltrexone (LDN)?

There is no human trial of LDN with a longevity or healthspan endpoint. The only lifespan evidence is invertebrate: a 2024 iScience study reported a 17.6 percent median lifespan extension and improved mobility in C. elegans at 2.5 micromolar via SKN-1 (the worm NRF2 orthologue), with no benefit at high dose. That is a worm result, not a mammalian or human one. In humans the best-developed dataset is fibromyalgia pain, where a 2025 systematic review and meta-analysis of five RCTs found a significant reduction in pain scores but small samples and limited robustness. For long COVID a 2025 systematic review found zero RCTs, only four observational pre-post studies (n=155), with low certainty of evidence. A 2026 narrative review in Advances in Therapy covering 105 studies including 15 RCTs concluded that early positive uncontrolled findings were rarely replicated in placebo-controlled trials and that the literature is dominated by case reports and small feasibility studies prone to publication bias. What the evidence does NOT show: any effect on ageing biomarkers, biological age, mortality, or any healthspan outcome in humans. Anyone presenting LDN as a longevity intervention is extrapolating from a worm study and an anti-inflammatory mechanism story.

How strong is the evidence for Low-dose naltrexone (LDN)?

Preclinical. Evidence comes from laboratory or animal work, not from human trials.

Is Low-dose naltrexone (LDN) approved in Singapore?

Health Sciences Authority position on record: Not registered by HSA at low dose. The naltrexone-containing product identifiable in HSA's new drug approval listings is CONTRAVE (naltrexone 8 mg / bupropion 90 mg prolonged release), approved in 2022 as an anti-obesity preparation and classified prescription-only medicine. No HSA-registered product exists at the 1.5 to 4.5 mg LDN strength, so LDN in Singapore is a prescriber-initiated, extemporaneously compounded preparation: Amber Compounding Pharmacy (Singapore) states plainly that this dosage is not commercially available and that LDN is only available from a compounding pharmacy. Caveat: I could not verify from an HSA source whether standalone naltrexone 50 mg tablets are registered in Singapore, and I found no HSA guidance addressing low-dose naltrexone specifically.. An evidence grade and a regulatory approval are different questions.

Is Low-dose naltrexone (LDN) approved in Australia?

Therapeutic Goods Administration position on record: Naltrexone hydrochloride 50 mg oral tablets are TGA-registered on the ARTG (for example NALTREXONE GH, ARTG 128710, registered 2007; NALTREXONE ASTRON, ARTG 386567, registered 2023), indicated for alcohol dependence within a comprehensive treatment programme and as adjunctive therapy in maintenance of formerly opioid-dependent patients. Low-dose use is entirely off-label: no TGA-registered product exists at LDN strengths, so LDN must be extemporaneously compounded by a compounding pharmacy on a doctor's prescription and is not PBS-subsidised. National Custom Compounding, an Australian compounding pharmacy, states LDN "is considered an off-label therapy in Australia" and must be prescribed by a doctor. There is no TGA approval, and no Special Access Scheme pathway is involved, since off-label prescribing of a registered ingredient via compounding is a normal prescriber-responsibility route.. An evidence grade and a regulatory approval are different questions.

What else is Low-dose naltrexone (LDN) called?

Also known as LDN, naltrexone low dose, low-dose naltrexone.