Health Topics / Safety & Harms
Safety & Harms 49 topics · 63 claims
Is it safe? Every claim about harm, toxicity and side effects, gathered from across the site.
Glyphosate 6
Does glyphosate cause non-Hodgkin lymphoma?
Not from food. For heavily exposed applicators the highest-exposure group does show elevated risk, though the biggest long-term study found none. A 2026 study suggests the other ingredients in the formulation, not glyphosate itself, may be what matters.
glyphosate causes non-Hodgkin lymphoma
Does glyphosate disrupt human hormones?
Several studies find lower sex hormones in people with more glyphosate in their urine, but they cannot show which causes which, and most come from the same survey. Much of the animal evidence tested Roundup rather than glyphosate, and the other ingredients may be doing the work.
glyphosate alters human hormone levels
Does glyphosate cause kidney disease?
A kidney disease epidemic in farming regions of Sri Lanka and Central America prompted this, but the leading explanation is heat stress and dehydration in outdoor workers. The one study measuring both found the job mattered and glyphosate levels did not.
glyphosate causes kidney disease
Is the glyphosate in your food harming you?
The studies suggesting harm are mostly the same 4,700 people analysed over and over, and they share a flaw: poor kidney function raises urinary glyphosate, so cause and effect may run backwards. Measured dietary intake sits at a tiny fraction of the safety limit.
glyphosate residues causes adverse health effects
Does glyphosate damage your gut bacteria?
The theory is sound, because gut bacteria have the exact pathway glyphosate blocks. But it has never been tested in a single human. The evidence is rodents, mostly at doses far above anything you would eat.
glyphosate alters gut microbiome
Does glyphosate cause celiac disease?
This comes from one 2013 paper that noticed glyphosate use and celiac diagnoses rose at the same time. Nobody has ever tested it. Celiac diagnoses also rose because doctors started screening for it.
glyphosate causes celiac disease
Testosterone therapy (TRT) 3
all 10 testosterone therapy (trt) claims →Is testosterone therapy safe for the prostate?
On the cancer question, the modern evidence is reassuring: the old fear that testosterone feeds prostate cancer is not supported. Randomized trials, large registries, and even prostate-cancer-survivor studies show no increased risk, and some show lower risk. The main caveat is that the trials weren't long enough to be the final word, so men on testosterone should still get routine PSA/prostate monitoring.
testosterone therapy does not increase prostate cancer risk
Is testosterone therapy safe for your heart?
Mostly reassuring, not fully settled. The big 2023 TRAVERSE trial found no increase in major cardiac events (heart attack, stroke, cardiac death) — putting an old scare to rest — but it did find more atrial fibrillation and blood clots in the lungs. So: probably safe for major events in the right patients, with a real, unresolved signal for irregular heartbeat and clots.
testosterone therapy does not increase cardiovascular risk
Is testosterone therapy safe for the heart in older at-risk men?
The large TRAVERSE RCT found TRT non-inferior to placebo for major cardiac events over about 3 years, though it raised atrial fibrillation, pulmonary embolism, and acute kidney injury and does not speak to longer horizons.
testosterone replacement therapy is-non-inferior-to-placebo-for major adverse cardiac events in older men with CV risk
Aspartame 2
all 5 aspartame claims →Creatine 2
all 15 creatine claims →Is creatine safe to take long-term?
Yes — it has one of the strongest safety records of any supplement, with no harm to kidney, liver, or heart markers in healthy adults across trials lasting years. Claims that literally everyone should take it, including pregnant or clinical populations, go further than the evidence.
creatine is safe for healthy adults
Does creatine damage your kidneys?
No — not in healthy people at normal doses. Creatine nudges up a blood marker (creatinine) that can look like kidney trouble on a test, but meta-analyses and even genetic studies find no actual harm. Existing kidney disease is a separate conversation with your doctor.
creatine does not harm kidney function
Fermented vegetables (kimchi, sauerkraut) 2
all 5 fermented vegetables (kimchi, sauerkraut) claims →Do kimchi and pickled vegetables raise stomach-cancer risk?
The evidence says yes, they're associated with higher stomach-cancer risk — several studies point the same way, and kimchi specifically showed about double the odds in Korean populations. The likely cause is the salt and nitrites from pickling, not the vegetables themselves (fresh vegetables actually lower risk). It's mostly lower-quality data, so it's a real red flag rather than proof — but it means fermented veg aren't a free pass, especially in large, very salty amounts.
fermented vegetables increases gastric cancer risk
Do pickled vegetables raise throat/esophageal-cancer risk?
Possibly — two analyses found pickled vegetables roughly doubled the odds of esophageal cancer, along the same salt/pickling pathway. But the signal weakened to non-significant in the strongest (prospective) studies, so it's a leaning concern rather than settled fact.
fermented vegetables increases esophageal cancer risk
Ketogenic diet 2
all 17 ketogenic diet claims →Does starting the ketogenic diet commonly cause side effects like constipation, nausea and fatigue?
Yes — the "keto flu" is real: constipation, nausea, vomiting and lethargy are commonly reported on initiation, usually mild and manageable but genuine.
ketogenic diet causes gastrointestinal and induction adverse effects
Does the keto diet raise bad cholesterol?
Yes, often dramatically in lean people, though whether that rise carries normal heart risk is unsettled.
ketogenic diet increases LDL cholesterol
Non-nutritive sweeteners 2
all 8 non-nutritive sweeteners claims →Do artificial sweeteners harm your heart and metabolism?
Probably not — the scary signal is likely backwards, and swapping sugar for them looks neutral in trials.
non-nutritive sweeteners causes cardiometabolic harm
Do artificial sweeteners cause cancer?
The evidence says no. Large reviews have repeatedly looked and found no cancer link at the amounts people actually consume. The scare traces back to old rat studies using doses far beyond any human diet. This is one of the clearer 'debunked' answers in the library.
non-nutritive sweeteners increases cancer risk
Pesticide exposure 2
Do pesticides cause Parkinson's disease?
For farm workers and people living near sprayed fields, this is one of the more credible pesticide risks, particularly for paraquat. But no study has ever linked it to the residue levels on supermarket food.
pesticide exposure increases Parkinson's disease risk
Do pesticides make it harder to conceive?
For people working with them, probably. For ordinary consumers the evidence is thin, relies on indirect measures, and one large study found the opposite of what you would expect.
pesticide exposure decreases fertility
Quercetin 2
all 17 quercetin claims →Is quercetin bad for your kidneys?
The evidence runs the other way: across sixteen studies quercetin protected kidneys from other damage rather than causing harm. The lone injury signal used injected, not oral, doses in rodents. What is genuinely missing is a proper human high-dose safety trial.
quercetin causes kidney injury
Can quercetin interfere with prescription medications?
It blocks the CYP3A4 enzyme in the lab, and raises drug levels in rats. Whether that happens in people at supplement doses is untested, and in the one direct check the effect did not even carry across two similar drugs. Mention it to your prescriber if you take a narrow-margin medication.
quercetin inhibits CYP3A4