Every published Signal Record

Alcohol is a Group 1 carcinogen with well-established, dose-dependent harms: cancer, high blood pressure, atrial fibrillation, liver disease, disrupted sleep, and worsened sleep apnoea. The widespread belief that moderate drinking protects the heart came from studies whose abstainer groups included people who had quit because they were already ill — and it does not survive the methods designed to correct for that. The absolute risks at low intake are small, and this is a personal choice; BioSignal's job is to make the trade-off legible.

Antibiotics are among the most valuable drugs ever discovered — for a bacterial infection they can be the difference between recovery and death. They do nothing at all for viral illness, which is what most coughs, colds, sore throats and sinus infections actually are. The genuinely useful thing to understand is not whether antibiotics work but whether your illness is the kind they work on: taking them for a virus cannot help, exposes you to real side effects, disturbs your gut, and makes your own next infection more likely to be resistant. This page is about the drug class and when it earns its place — not a tool for deciding whether a particular illness is bacterial, which is a job for a clinician.

Anticoagulants prevent and treat blood clots, and in atrial fibrillation they reduce stroke risk by roughly two-thirds — one of the largest treatment effects in medicine. Direct oral anticoagulants (DOACs) have largely replaced warfarin for most indications, with less intracranial bleeding and no routine monitoring. But two indications still require warfarin absolutely — mechanical heart valves and antiphospholipid syndrome — and aspirin, despite being widely believed to be a 'blood thinner', is not adequate stroke prevention in atrial fibrillation.

SSRIs and SNRIs are among the most-prescribed medications in the world, and the public conversation about them is unusually poor in both directions. The serotonin — or 'chemical imbalance' — theory of depression is not supported by the evidence. That is true, and it is not the same as saying the drugs don't work. Large analyses of hundreds of randomised trials find they do beat placebo. The honest complication is that the average benefit is modest, that it grows with severity, that sexual side effects are common and under-discussed, and that stopping can cause a real and sometimes protracted withdrawal that was denied for far too long.

Benzodiazepines work. For acute anxiety, panic, seizures, alcohol withdrawal and procedural sedation they are fast, reliable and sometimes life-saving, and there are situations where they are clearly the right drug. They also carry real risks that scale with dose, duration, age and what else is on board — and two of those risks are severe: combined with opioids or alcohol they suppress breathing, and stopped abruptly after regular use they can cause seizures. The honest account sits between the two stories people are usually told. They are not harmless anxiety pills, and they are not uniformly destructive. Most people taking them are taking them as prescribed — misuse accounts for about 17% of use in the US, which means roughly 83% is not. The distinction that does the most work on this page is between physical dependence, which is expected and is not addiction, and a substance-use disorder, which is a different thing.

Lowering blood pressure with medication is one of the best-established, highest-value interventions in all of medicine: it prevents strokes, heart attacks, heart failure, kidney disease, and dementia, and it saves lives. The evidence is not in doubt. The real problem is not efficacy but adherence — roughly half of people stop taking them, usually because the condition is silent and the tablets feel like the illness.

Caffeine is the world's most widely used psychoactive compound, and it is a well-evidenced aid for alertness and endurance performance that is safe for most healthy adults within customary limits.

Creatine is a naturally occurring compound central to short-term muscle energy, and creatine monohydrate is among the most well-supported supplements for strength and high-intensity performance.

Ezetimibe lowers LDL cholesterol by blocking its absorption in the gut. On its own the reduction is modest (~15–20%), but added to a statin it further lowers LDL and reduces cardiovascular events (IMPROVE-IT). It is inexpensive, generic, and very well tolerated — a useful add-on and an option when statins can't be fully used.

Hormonal contraception is safe and effective, and the differences between methods matter far more than the marketing suggests. In TYPICAL use — real people, real lives — long-acting methods (implant, IUS, IUD) fail in under 1 in 100 users per year, while the pill fails in about 7. The combined pill carries a real but small increase in blood-clot risk, is absolutely contraindicated in migraine with aura, and — the half of the cancer story that rarely gets told — substantially reduces the lifetime risk of ovarian and endometrial cancer.

Inhaled corticosteroids are the cornerstone of asthma treatment: they reduce exacerbations, hospital admissions and deaths, and modern guidelines now recommend that essentially everyone with asthma — including mild asthma — receives inhaled-steroid-containing therapy rather than a reliever alone. They are also the inhaler people quietly stop taking, because it does nothing they can feel. In COPD the story is different and narrower: they help a defined subgroup, guided by blood eosinophils, and they raise the risk of pneumonia.

Levothyroxine is effective, inexpensive replacement therapy for an underactive thyroid, and for overt hypothyroidism it is genuinely transformative. The difficulties are at the margins: mild (subclinical) hypothyroidism is often treated without benefit, over-replacement carries real risks, and a subset of patients remain symptomatic despite a normal TSH — a problem the popular alternatives have not solved.

Melatonin is the hormone the brain releases at night to signal biological night-time, and as a supplement it works mainly as a body-clock (chronobiotic) signal for correcting sleep timing rather than as a sedative for ordinary insomnia.

Menopausal hormone therapy is the most effective treatment for hot flushes and night sweats, and it prevents bone loss. For most women under 60, or within 10 years of menopause, benefits outweigh risks and the absolute risks are small. The 2002 headlines that collapsed its use were a misreading — and the resulting under-treatment caused real, avoidable suffering.

Metformin is the long-standing first-line medication for type 2 diabetes: it lowers glucose by reducing hepatic glucose output and improving insulin sensitivity, is inexpensive and weight-neutral, and reduces progression from prediabetes to diabetes. Its cardiovascular benefit is plausible but modest in modern evidence, and its popular 'longevity drug' reputation is not yet established.

NSAIDs genuinely work for osteoarthritis and short-term pain, and they are among the more effective analgesics available. They also carry real cardiovascular, gastrointestinal and kidney risks — and those risks run in opposite directions between drugs, so there is no single 'safest' NSAID, only trade-offs. The most useful thing on this page is not a warning: it is that paracetamol, the drug people switch to in order to be careful, barely works for the conditions they are switching for.

PCSK9 inhibitors are injectable therapies that produce very large additional LDL/ApoB reductions (~50–60% on top of a statin) and reduce cardiovascular events in high-risk patients (FOURIER, ODYSSEY). They also modestly lower lipoprotein(a). They are powerful add-ons for high-risk patients not at goal, limited chiefly by cost and access.

Psyllium is a soluble, gel-forming fibre with unusually good evidence across several unrelated outcomes: it relieves constipation, improves IBS symptoms, modestly lowers LDL cholesterol and ApoB, and improves glycaemic control. It is cheap, well tolerated, and consistently underrated — an uncommon case where the science is stronger than the hype.

Retinoids are vitamin A derivatives and they are the most strongly evidenced topical treatment in dermatology — for acne and for photoaging, with randomised trial support and regulatory approval behind both. They are also, revealingly, among the cheapest things in the skincare aisle. The confusion the industry profits from is that 'retinol' and 'retinoid' sound like synonyms: only retinoic acid is active, prescription tretinoin is retinoic acid, and cosmetic retinol must be converted twice inside the skin to become it — making it substantially weaker and, unlike a drug, not required to tell you how strong it is.

Semaglutide reliably produces substantial weight loss (~15% in obesity trials) and reduces major cardiovascular events, but it is a chronic medication with gastrointestinal side effects, lean-mass and regain concerns, and long-term data still accruing.

SGLT2 inhibitors lower glucose by increasing urinary glucose excretion, but their importance comes from strong randomized evidence that they reduce heart-failure hospitalizations and slow chronic kidney disease — benefits that hold even in people without diabetes. They are a practice-changing class, with manageable risks (genital infections; rare euglycemic ketoacidosis).

Stopping smoking returns more health than almost any other single change a person can make: smokers lose at least a decade of life expectancy on average, and quitting before 40 avoids roughly 90% of the excess risk of death from continuing. The obstacle is rarely wanting to stop — it is that willpower alone is the weakest available method, and the strongest ones are the least understood. On current evidence the most effective options are varenicline, nicotine e-cigarettes and cytisine, with combination nicotine-replacement therapy close behind; a single patch or a single lozenge on its own is markedly weaker, and behavioural support adds to all of them. The belief that does the most damage is that nicotine replacement is as dangerous as smoking. It is not: nicotine drives the addiction, but it is the burning of tobacco that does the killing.

Statins lower LDL cholesterol and ApoB and, across dozens of large randomized trials, reduce major cardiovascular events and mortality in proportion to how much LDL is lowered. They are among the best-evidenced medications in all of medicine, with a safety profile that is well characterized and, for most people, favorable.

Tirzepatide produces very large weight loss (up to ~21% in obesity trials) and outperformed once-weekly semaglutide on HbA1c and weight in a head-to-head diabetes trial, at the cost of class-typical GI effects and still-accruing long-term data.

Vitamin C is an essential nutrient with a famous claim attached to it that the evidence does not support: taken regularly, it does not reduce your chance of catching a cold. That question has been asked properly, many times, and answered. What survives the evidence is quieter and more useful — it shortens a cold slightly, it halves cold incidence in people under extreme physical stress, it cures scurvy, and it markedly improves iron absorption from plant foods. Megadoses mostly become urine, because absorption saturates.

Vitamin D is a hormone precursor essential for correcting deficiency and supporting bone mineralization, but large trials show it does not broadly prevent disease in people who already have enough.

Whey is an exceptionally high-quality, convenient protein source that genuinely supports muscle, strength, recovery, and — during dieting — satiety, though total daily protein matters far more than the powder, brand, or timing.

Zinc is an essential mineral with genuinely strong evidence in specific settings — treating childhood diarrhoea, slowing macular degeneration as part of the AREDS formulation, and modestly shortening the common cold. It raises testosterone only in men who are deficient. In replete people, supplementing does nothing useful, and excess zinc causes copper deficiency.

Collagen supplements have genuine but modest evidence for skin and emerging signals for bone and tendon — but the field is dominated by manufacturer-funded, short-term studies, and collagen is not a complete protein.

Glucosamine and chondroitin are among the most purchased supplements in the world, and the highest-quality independent trials have not found meaningful benefit over placebo for osteoarthritis pain or joint structure. This is not thin evidence — it is good evidence pointing the wrong way. They are very safe, which is why the honest verdict is 'it probably won't help' rather than 'don't'. What does help — exercise and weight management — is well established and free.

Intermittent fasting produces real weight loss — but head-to-head trials find it roughly equivalent to ordinary calorie restriction, not superior. The eating window is not metabolically magical; it is a rule that helps some people eat less, which is a legitimate and useful thing to be. The autophagy and longevity claims rest on animal data. If it suits you, it is a reasonable approach; if it doesn't, you are not missing out on anything the evidence supports.

Magnesium is an essential mineral and enzymatic cofactor whose benefits concentrate where a genuine deficiency exists to correct; a few specific uses are well-grounded while several popular consumer claims remain weak or unproven.

NAC is a life-saving intravenous antidote for paracetamol (acetaminophen) overdose — an essential medicine that prevents liver failure. That is where its strong evidence begins and very nearly ends. As an oral supplement for 'detox', immunity, or longevity, it has no demonstrated benefit. There is genuine emerging evidence in a narrow set of psychiatric conditions, notably compulsive hair-pulling and skin-picking.

Omega-3 is not one thing: the marine fats EPA and DHA reliably lower triglycerides and modestly reduce preterm birth, but routine fish oil does not prevent cardiovascular disease in the general population, and high doses carry an atrial-fibrillation trade-off.

Peppermint oil relaxes intestinal smooth muscle, and enteric-coated preparations have modest but real randomised evidence for reducing abdominal pain in IBS. It is best understood as a plant-derived antispasmodic for a specific symptom — not a general gut-health supplement, and not a treatment for the underlying disorder.

Retatrutide is a promising but investigational triple agonist with ~24% weight loss at 48 weeks in a phase-2 obesity trial; it is not approved, not available as an evaluated therapy, and its efficacy and safety are not yet established at the level of the approved incretins.

St John's Wort is one of the very few herbal supplements with real randomised evidence behind it: in mild-to-moderate depression it outperforms placebo and performs comparably to standard antidepressants, with fewer side effects. BioSignal says so plainly, because saying no to everything is not evaluation. But the same reason it is worth taking seriously is the reason it is genuinely hazardous — it is a potent inducer of drug-metabolising enzymes, and it strips other medications of their effect. Documented consequences include organ-transplant rejection and contraceptive failure. This is not a gentle herb, and 'natural' explains nothing.

Tesamorelin genuinely reduces visceral (and liver) fat in HIV-associated lipodystrophy in randomized trials and is FDA-approved for that use, but its effects require continued dosing, raise IGF-1, and are not established for the general population.

Testosterone replacement is an effective, evidence-based treatment for men with genuine hypogonadism — confirmed low morning testosterone plus symptoms. It is not an anti-ageing therapy, and it is not established to benefit men with normal levels. Much 'low testosterone' is functional and reversible, and therapy suppresses fertility — a consequence that is routinely under-disclosed.

Alpha-GPC is a choline-donating supplement popular for cognition and, among athletes, for power output. Human efficacy evidence for cognitive enhancement in healthy adults is limited and low-quality. Importantly, a large observational analysis has raised a possible association with increased stroke risk — unconfirmed, but a genuine reason for caution given the weak benefit evidence.

Apple cider vinegar has one modest, reproducible effect — taken with a carbohydrate meal, it blunts the post-meal glucose rise. Almost every other claim made for it, including meaningful weight loss, lower cholesterol, 'detoxification' and gut health, is unsupported. It is also a strong acid, and the documented harms — dental erosion, oesophageal injury, and delayed gastric emptying — are more substantial than the benefits.

Ashwagandha has the most credible evidence of the popular hormonal supplements: small randomised trials report reduced stress and anxiety scores and lower cortisol. But the trials are small, short, and often industry-linked, the testosterone evidence is weak, and there is a genuine liver-injury signal that has prompted regulatory warnings. It is not a hormone therapy, and it should not be treated as one.

Berberine is a plant compound sold as a supplement that shows modest glucose- and lipid-lowering effects in small, mostly short-term human studies. It is frequently marketed as 'natural metformin,' but the evidence is limited, product quality varies, it interacts with several medications, and it has no long-term outcome data.

Boron is a trace element that is not established as essential for humans. Its reputation as a testosterone booster rests on a handful of very small studies in which boron lowered SHBG — raising the free fraction of testosterone without clearly raising total testosterone, and without any demonstrated clinical benefit. It is a staple of testosterone stacks and one of the least supported ingredients in them.

Despite heavy marketing and a large preclinical literature suggesting tissue-healing effects, BPC-157 has no human trials, is not approved, and its human efficacy and safety are unestablished — BioSignal cannot recommend it.

Citicoline supplies choline and supports membrane phospholipid synthesis. It has the most credible evidence of the popular cognitive supplements — chiefly in vascular cognitive impairment and post-stroke settings, where results are still mixed — while evidence for enhancing cognition in healthy adults is weak. It is a prescription medicine in some countries and a supplement in others.

CJC-1295 does what a GHRH analog should — raise GH and IGF-1 — but 'raises a hormone' is not the same as 'improves health,' and there are no human outcome trials, no approval, and unknown safety.

CoQ10 is mostly bought to relieve statin-related muscle aches — and randomised trials have repeatedly failed to show that it does. That belief is understandable, because statins do lower CoQ10, but the effect on symptoms has not materialised when tested. There is a more interesting signal elsewhere: a randomised trial in heart failure reported fewer cardiovascular events and lower mortality, a genuinely serious finding that has not been replicated at scale.

Curcumin is among the most-studied natural compounds ever, and has never produced an approved therapeutic — for structural reasons. It is barely absorbed, chemically unstable, and a well-documented false positive in laboratory assays, which is why it appears to 'work' on almost everything in a dish. The most credible human evidence is modest pain relief in osteoarthritis. There is also a genuine liver-injury signal, particularly with high-absorption formulations.

DHEA is a hormone made by the adrenal glands that declines steadily with age — which is why it became the original anti-ageing supplement. It has since been well tested for that purpose and failed: a rigorous trial in older adults found no benefit for body composition, physical performance, insulin sensitivity, or quality of life. It is, however, an FDA-approved prescription medicine as a vaginal insert for painful sex after menopause, and it has a genuine role in adrenal insufficiency.

GHK-Cu has interesting skin-repair biology and appears in cosmetics, but the influential reviews carry undisclosed commercial conflicts, the topical human evidence is thin, and there are no human trials of injected/systemic GHK-Cu for any health outcome.

Glutamine is the main fuel for the cells lining the intestine, which is why it anchors the 'leaky gut' supplement category. But the body makes it in abundance, healthy people are not deficient, and supplementation has not been shown to improve gut health in healthy adults. The evidence that does exist sits in clinical settings — severe illness, short bowel syndrome, post-infectious IBS — not on the supplement shelf.

Ipamorelin selectively stimulates growth-hormone release in preclinical models, but its one human clinical trial failed, it has no evidence for body-composition or recovery benefit, and it is an unapproved, sport-prohibited research chemical.

L-theanine is an amino acid in tea that produces a mild sense of calm alertness. Small, short trials suggest it reduces subjective stress and — most consistently when combined with caffeine — modestly improves attention. It is well tolerated, but it is not a durable cognitive enhancer and has no evidence for preventing cognitive decline.

Lion's mane is a mushroom widely marketed for cognition and 'nerve regeneration.' Its preclinical story — stimulating nerve growth factor — is genuinely interesting, but human evidence is limited to small, short, methodologically weak trials. There is no good evidence it enhances cognition in healthy adults or prevents cognitive decline.

MOTS-c is a scientifically fascinating 'exercise-linked' mitochondrial peptide with strong mouse data and human observational signals, but there are no trials of administering native MOTS-c to people, and it is an unapproved, experimental compound.

NAD+ is a fundamental cellular coenzyme involved in energy production, DNA repair, and cellular signaling, while evidence for NAD+-boosting therapies remains promising but incomplete.

Probiotics are live microorganisms sold for 'gut health,' but the category label is misleading: effects are strain-specific and condition-specific, not general. A few strain–indication pairs have real evidence — antibiotic-associated diarrhoea, pouchitis, infant colic — while routine use for general gut health in healthy adults is not supported. Fibre feeds your existing microbiome more reliably than a capsule reseeds it.

TB-500 borrows credibility from the real biology of thymosin β4, but the fragment sold online has no human efficacy trials, is not approved, is WADA-prohibited, and its human safety is unknown.

Tongkat Ali is marketed as a natural testosterone booster. The human evidence is small, short, and concentrated in men who were stressed, subfertile, or already hypogonadal — where a modest testosterone rise is unsurprising and not the same as raising testosterone in a healthy man, which has not been shown. Product quality is a genuine concern, with heavy-metal contamination reported.

Vitamin K2's story is mechanistically beautiful: it activates proteins that inhibit artery calcification and bind calcium into bone, so it should move calcium from your arteries to your skeleton. It is also the clearest example in BioSignal of a beautiful mechanism failing in trials. Randomised studies of K2 for vascular calcification have been essentially null, and the fracture evidence outside high-dose Japanese use is disappointing. It is well tolerated — but it is dangerous with warfarin.