Supplements to Support Immune System

A 28-amino-acid immunomodulating peptide. Unlike most peptides marketed online, this one is a genuine APPROVED DRUG (thymalfasin / Zadaxin) in ~35 countries — though NOT in the US — for chronic hepatitis B/C and as a vaccine adjuvant, and it has real human RCTs and meta-analyses. Honest framing: the best evidence is for hepatitis B/C antiviral response (often as an add-on to interferon/entecavir) and immune restoration in critically ill patients; sepsis and COVID-19 data are mixed (one COVID meta-analysis found benefit, another found none overall). This approved/trial evidence is NOT the same as the 'anti-aging / immune-boost' marketing attached to grey-market injectable vials.

A synthetic pentapeptide (Arg-Lys-Asp-Val-Tyr) reproducing the active site of the thymic hormone thymopoietin. Unlike grey-market peptides, thymopentin was a genuinely registered immunomodulator drug — marketed as Timunox in Italy and widely used in China — so it has real Western randomized trials behind it, not just anecdote. The strongest data are small placebo-controlled RCTs in active rheumatoid arthritis from the 1980s (Lancet, German multicentre) showing short-lived symptomatic improvement, and a 352-patient double-blind HIV trial where it modestly delayed disease progression. But the evidence is old, heterogeneous, and short-duration; benefits faded weeks after stopping; it failed as a vaccine adjuvant in at least one trial; and it is NOT an FDA-approved drug or a dietary supplement. Modern meta-analyses pooling Chinese adjuvant-therapy trials (tuberculosis, lung cancer) report benefits but are dominated by low-quality, unblinded studies. Treat this as a real but weakly-evidenced legacy immunomodulator, not a proven supplement.

A polypeptide complex extracted from the thymus, registered as an immunomodulator medicine in Russia and several CIS countries — so unlike grey-market peptides it has real (if mostly Russian-language and low-quality) human studies. Thymalin is promoted to 'normalize' immune function by stimulating T-lymphocyte differentiation, with claimed uses in respiratory infections, COVID-19 adjuvant therapy, and even longevity. The headline evidence is striking but weak: an open-label Russian cohort reported a 2-fold drop in mortality in elderly people treated with thymalin (± a pineal peptide) over 6-8 years, and unblinded COVID-19 series reported lower hospital mortality when added to standard care. Almost none of this is double-blind, placebo-controlled, or replicated outside Russia/CIS; sample sizes are small; mechanism work is largely in-vitro. Western regulators have NOT approved it. Treat the longevity and mortality claims with strong skepticism.

A grey-market research peptide with NO completed human trials — every efficacy result below is from mice, rats, or cells. KPV is the C-terminal tripeptide (Lys-Pro-Val) of α-melanocyte-stimulating hormone (α-MSH), and it carries α-MSH's anti-inflammatory activity without the pigment-inducing effect. In mouse and rat models of ulcerative colitis it consistently reduces gut inflammation, and reviews flag related melanocortin tripeptides as candidates for skin-wound healing. But KPV has never been tested in a completed human efficacy trial, it is not an approved drug or a lawful dietary supplement, and it is sold online as an unregulated research chemical with no quality control. Its human dosing, route, and long-term safety are unknown. This entry exists to inform, not to recommend.

An FDA-approved mTOR-inhibitor immunosuppressant (sirolimus, Rapamune) taken off-label for longevity. It is the most robustly lifespan-extending compound in animal studies across species, but human longevity benefit is unproven — the human data are short-term immune/biomarker trials, and it carries real immunosuppression risks. A prescription drug, not a supplement.

A rapamycin analog (rapalog, RAD001) approved as an oncology drug (Afinitor) and transplant immunosuppressant (Zortress). It is the mTOR inhibitor with the cleanest human geroscience signal: randomized trials in older adults showed it improved vaccine response and reduced infections — an immune-aging benefit, NOT demonstrated lifespan extension. A prescription immunosuppressant, not a supplement, and its later phase-3 respiratory-illness sibling trial missed its endpoint.

An opioid-antagonist drug (naltrexone) taken off-label at very low doses (~1.5–4.5 mg) for chronic pain, fibromyalgia, and autoimmune/inflammatory conditions. The leading idea is that a brief nightly opioid-receptor blockade triggers a rebound rise in endorphins and dampens glial/TLR4 inflammation. Human trials are mostly small pilots with mixed results — a real but preliminary signal in fibromyalgia, weaker elsewhere. A prescription drug used off-label, not a supplement, and not a proven longevity drug.