🤷
Are Costco Supplements Good Quality?
Kirkland Signature vitamins are undeniably cheap, but their reliance on synthetic ingredients and poor-absorbing minerals means you get exactly what you pay for.
Search for categories and articles
Vitamins, probiotics, fish oil, collagen, and greens powders — the supplement industry is largely unregulated. We dig into what works, what's contaminated, and what's a waste of money.
103 topics
Kirkland Signature vitamins are undeniably cheap, but their reliance on synthetic ingredients and poor-absorbing minerals means you get exactly what you pay for.
Buying vitamins on Amazon is convenient, but you might be swallowing expired ingredients, dangerous heavy metals, or completely fake pills.
Nearly half of top-selling protein powders fail strict heavy metal safety tests—and organic plant-based options are often the worst offenders.
A shocking 89% of sports supplements fail basic label accuracy tests, and the FDA rarely issues mandatory recalls.
Only a fraction of the thousands of supplement brands on the market actually pay for independent testing to prove what's in the bottle.
The supplement industry is wildly unregulated, but the NSF seal guarantees that what's on the label is actually in the bottle.
The USP Verified mark is the gold standard for supplement safety, but incredibly few brands actually earn it.
Only a fraction of supplements on the market actually contain what's on the label—here is how to know yours is one of them.
Nearly 30% of popular multivitamins fail independent testing—here is exactly what to look for to ensure your supplement is safe.
Nearly half of Americans believe the FDA approves supplements before they hit shelves—but the reality is a multi-billion dollar honor system.
More than 50% of popular supplements sold on Amazon fail active ingredient testing—here are the worst offenders.
The vitamins you see at the drugstore aren't the ones your doctor takes—here are the practitioner-grade brands that actually pass clinical scrutiny.
The popular personalized vitamin brand abruptly shut down in 2024—here's why quiz-based supplements are a red flag anyway.
They look stunning on Instagram, but it’s their rare USP verification and peer-reviewed clinical trials that actually justify the premium price tag.
It's one of the cheapest supplement brands at the pharmacy, but you're paying for synthetic vitamins and sugary fillers.
It's the #1 pharmacist-recommended vitamin brand in America, but does that drugstore price tag come with a hidden cost?
They’re the 'good cops' of the supplement world—running over 16,000 in-house tests every single month to guarantee purity.
Garden of Life holds the gold standard for supplement certifications, but recent 2024 and 2025 tests reveal alarming levels of lead in their most popular products.
Thorne is one of the only supplement brands that actually justifies its premium price tag, backed by an exclusive Mayo Clinic partnership and exhaustive testing.
Out of 50,000+ dietary supplements on the market, only a handful have decades of gold-standard human trials proving they actually work.
Stop wasting money on multivitamins. Here are the four evidence-backed supplements that actually move the needle.
The supplement industry wants you to buy 15 different bottles, but clinical data points to just three universal nutrient gaps.
Produce grown today has up to 38% fewer nutrients than it did in 1950, making 'food-first' nutrition harder than ever.
Americans spend $50 billion a year on vitamins, but a massive review of 84 studies found most of them do absolutely nothing for healthy adults.
A massive 2024 NIH study of 400,000 adults proves multivitamins won't help you live longer, but they might save your memory.
Yes, and it comes from lichen—a plant-based source that's just as effective as sheep's wool without the pesticide risk.
Independent testing reveals that up to 29% of vitamin D supplements fail quality checks, with some containing just 32% of what's on the label.
Taking high doses of vitamin D without K2 could be sending calcium straight into your arteries.
Vitamin D3 is up to 87% more effective at raising your blood levels than D2—so why do doctors still prescribe the weaker form?
5,000 IU is a therapeutic dose meant to correct a deficiency, not a daily multivitamin.
Vitamin D toxicity is a real and dangerous condition that can cause permanent kidney damage if you take mega-doses without blood work.
The official guideline is 600 IU per day, but functional medicine doctors say you need up to 5,000 IU to reach optimal levels—and neither works if you're missing two critical cofactors.
One fixes your body clock, the other calms your nervous system—here's how to actually choose.
Magnesium won't knock you out like a sleeping pill, but taking the right form can effectively turn off your racing mind at 2 a.m.
The popular fizzy powder is great for constipation, but recent independent testing found concerning levels of heavy metals.
Stop wasting money on cheap magnesium oxide—here are the top third-party tested brands that your body can actually absorb.
Taking more than 350mg of supplemental magnesium a day can lead to a condition called hypermagnesemia—and your kidneys bear the brunt of the burden.
Nearly 50% of Americans are deficient in magnesium—the exact mineral your brain needs to calm down.
Magnesium glycinate is the undeniable king of sleep supplements, while the cheap magnesium sitting in your medicine cabinet might just keep you on the toilet.
They're both highly absorbable, but taking the wrong one will either keep you awake or send you running to the bathroom.
Up to 75% of Americans are deficient in magnesium, but taking the wrong form will just give you expensive diarrhea.
Most healthy children don't need a daily probiotic, but specific strains can cut antibiotic-related diarrhea risk by 50%.
Align features a highly effective, science-backed probiotic strain, but it's wrapped in a capsule containing artificial colors and milk protein.
It's the most hyped gut supplement on the internet, but Seed's capsule-in-capsule technology actually backs up the marketing.
Up to 30% of probiotics fail independent lab testing because the bacteria are already dead.
78% of people taking one specific probiotic strain saw significant bloating relief—while most generic brands perform no better than a placebo.
You can't just take a random probiotic for bloating—you need the specific clinical strain that actually treats it.
Stop paying for 100-billion CFU probiotics—most people only need 1 to 10 billion for daily health, and the strain matters much more than the number.
Up to 99% of standard probiotics die in your stomach before they ever reach your gut.
You're probably taking the wrong strain for your symptoms—here's why most daily probiotics are a waste of money.
95% of children don't get enough Omega-3s—but the gummy supplement you're giving them might be rancid.
Nordic Naturals is arguably the most trusted fish oil brand on the market, but recent lawsuits have raised questions about their 'natural' claims.
45% of popular fish oil supplements test positive for rancidity. Here are the brands that actually pass purity and freshness tests.
Fish don't actually make omega-3s—they get them by eating algae, which means you can skip the fish entirely.
Krill oil is absorbed better, but you're paying up to 10x more for a fraction of the omega-3s.
Good news: Fish oil doesn't contain mercury. Bad news: It might contain other toxins that are actually worse.
A shocking 68% of flavored fish oil supplements sold in the US exceed safe oxidation limits—meaning they are already rancid before you buy them.
While omega-3s are proven to support heart health, up to 45% of fish oil supplements on the market are rancid before you even open the bottle.
A major independent study found that 64% of top-selling collagen supplements contain measurable levels of arsenic.
The internet's favorite collagen powder recently hid a lawsuit-blocking arbitration clause under its lid—here's the truth about its heavy metal history.
64% of top-selling collagen supplements contain measurable levels of arsenic—here's how to find the clean ones.
Marine collagen absorbs 1.5 times faster than bovine collagen, but it comes with a much higher risk of heavy metal contamination.
There are 29 types of collagen in your body, but only three actually matter for your supplement routine.
Whole collagen is too large for your body to absorb—but hydrolyzed collagen peptides actually cross the intestinal barrier intact.
Science says yes, but only if you buy the right type—and dodge the 37% of brands contaminated with lead.
One is a $99 luxury habit and the other is a TikTok trend—but both hide their ingredients behind proprietary blends.
The TikTok-famous greens powder tastes great, but a closer look at the label reveals heavily under-dosed ingredients and controversial fillers.
AG1 passes strict heavy metal tests, but hides its most hyped ingredients behind proprietary blends.
Most greens powders hide cheap fillers behind 'proprietary blends'—and up to a third contain alarming levels of lead.
Recent independent tests found that 12 popular greens powders exceeded California's strict limits for lead without warning labels.
A standard 10-gram scoop of greens powder contains less than a fifth of your daily recommended vegetables—and strips away the most important nutrient of all.
At $3 a scoop, you're paying a premium for a fraction of a salad—and potentially a daily dose of heavy metals.
Most greens powders provide less than one-fifth of your daily vegetable needs—and many contain concerning levels of lead.
Tongkat Ali works, but up to 36% of products on the market contain dangerous levels of mercury and lead.
Real Mushrooms passes the strict heavy metal tests, but their China-based sourcing might surprise you.
Lion's mane shows promise for older adults, but healthy people are often paying premium prices for ground-up grain.
Not necessarily—while KSM-66 is the most studied, your ideal ashwagandha depends on whether you want energy or sleep.
Recent laboratory testing reveals that 28% of ashwagandha supplements exceed safe limits for toxic heavy metals like lead and arsenic.
Ashwagandha can increase your thyroid hormones by over 40%—which is either exactly what you need, or downright dangerous.
Independent testing reveals that up to 28% of ashwagandha supplements exceed safe limits for lead and other heavy metals.
Denmark banned it, doctors are warning about liver damage, and users report severe emotional numbness. Here is what the science actually says.
Clinical trials show certain herbs can drop your cortisol by up to 30%, but the supplement aisle is flooded with under-dosed marketing hype.
A shocking 88% of melatonin gummies are inaccurately labeled—here is what to take instead for deep, restorative sleep.
Taking 10mg of melatonin floods your body with up to 33 times more of the sleep hormone than it naturally produces.
Your brain only produces 0.1 to 0.9 mg of melatonin per night, yet most supplements pack 10 times that amount.
Melatonin won't cause physical addiction, but high doses and daily use can create a strong psychological dependency.
88% of melatonin gummies contain drastically different doses than their labels claim—some with up to 347% more melatonin.
80% of women experience hot flashes, but the most popular herbal remedy on shelves has been linked to liver damage.
Targeted nutrients can increase clinical pregnancy rates by up to 14%, but most 'fertility blends' are under-dosed marketing gimmicks.
It's one of the most comprehensive prenatals on the market, but you'll have to swallow 8 capsules a day to get the benefits.
Ritual's minimalist prenatal checks all the purity boxes, but it intentionally leaves out critical nutrients like Vitamin C and Calcium.
DHA is crucial for fetal brain development, but stuffing it into your daily multivitamin isn't always the best approach.
Up to 40% of people have a genetic mutation that prevents them from properly absorbing standard folic acid.
A shocking 83% of prenatal vitamins contain detectable lead, and most are missing the #1 nutrient for fetal brain development.
Nearly 30% of multivitamins fail third-party testing, and taking the wrong one could quietly damage your organs.
Multiple high-quality studies confirm this popular prostate supplement works no better than a placebo.
Beta-sitosterol is clinically proven to improve urinary flow, but the most popular prostate supplement on the market is basically a placebo.
A massive review of 50 top-selling testosterone supplements found that only 25% have data to back their claims—and 10% contain ingredients that actively lower your testosterone.
Hiya fixes the biggest problem with kids' vitamins: they swapped the sugar-loaded gummy for a dentist-approved, zero-sugar chewable.
They boast a Clean Label Project Purity Award and premium nutrients, but standard versions still hide a sugary secret.
Most kids' vitamins are basically candy in disguise—here are the clean options that actually work.
They look like candy, taste like candy, and rot your kid's teeth exactly like candy.
Parents spend over $20 billion a year on children's vitamins, but the AAP says most healthy kids don't actually need them.