PrimeDigger investigations
Wellness Guides: Supplements, Cooking Oils and Energy Drinks Checked
Supplements, wearables, sleep products, and health gadgets — checked against the research, not the marketing.
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Wellness products and health claims, checked against the research.
We check supplements, drinks, cooking oils and gadgets against studies, third-party lab results and the label, not the marketing. Pick a topic below. Our guides are for information only, not medical advice (see our health disclaimer).
Cooking oils and fats
Which oil to use depends on the job: everyday cooking, deep frying or a quick egg.
- Healthiest oil to cook with: seven oils ranked
- Best oil for frying: picks for deep frying and pan frying
- Healthiest oil to fry eggs: olive oil, avocado oil or butter
- Is beef tallow healthy?: what the science says for cooking
- Beef tallow for skin: benefits, risks and the vitamin myth
Supplements
Supplements are lightly regulated, so we look for third-party testing and what the studies actually show.
- Best creatine gummies: which ones passed lab tests
- Best creatine for women: why many gummies failed lab tests
- Creatine for menopause and women over 40: what studies show
- Protein powder without lead: how to avoid lead and other heavy metals
- Magnesium for sleep: does it work, and is glycinate best?
- Magnesium glycinate vs citrate: which form to take for sleep or constipation
- Magnesium glycinate side effects: what’s normal, the 350 mg limit and who should avoid it
- Types of magnesium: a chart of glycinate, citrate, oxide, threonate, malate and more, with what the evidence shows
- Does creatine make you bloated?: water weight vs stomach bloating, how long it lasts and how to avoid it
- Cortisol face: is it real?: what doctors call moon face, why your face is puffy and how cortisol is tested
- Is 10mg of melatonin too much?: what dose studies show
Energy drinks
- Healthy energy drinks: 19 popular cans scored on caffeine, sugar and sweeteners
- Is Celsius bad for you?: the label, the studies and the lawsuits
- Is Prime healthy?: the label, the lawsuits and the 200mg can
Sleep and stress
- Do stress relief products work?: what research says about five popular buys
Wellness gadgets
- Fitbit Air review: is it worth it, and how accurate is it vs Whoop?
- Best Fitbit Air bands: official, third-party and bicep bands
- Do red light therapy devices work?: what the research supports
- Cooling products that work: what helps in a heatwave
How we research: we don’t lab-test products. We read studies, third-party lab results, labels and official guidance, and we link our sources in every guide. Read our editorial policy.
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Best Probiotic for Women (2026): Only 5 of 16 Best-Sellers Name Their Strains
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Best Vitamin D Supplement (2026): Half the Best-Sellers Go Over the Safe Limit
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Best Multivitamin for Women (2026): Picks by Age, With and Without Iron
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Glass Skin: What It Really Is and a Simple Routine That Works (2026)
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Types of Magnesium: Which One Is Right for You? (Chart, 2026)
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Cortisol Face: Is It Real? What Doctors Say About Moon Face (2026)
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Does Creatine Make You Bloated? What the Research Shows (2026)
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Magnesium Glycinate Side Effects: What’s Normal and What’s Not (2026)
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Best Korean Skincare (2026): 6 Viral K-Beauty Products, Checked Against the Evidence
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PDRN Serum Review (2026): Does Salmon DNA Skincare Work? We Checked 9 PDRN Products
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COSRX Snail Mucin Review (2026): Does Snail Mucin Work? We Checked the Research and 10 Snail Products
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Sulwhasoo First Care Activating Serum Review (2026): We Checked the Ingredients, and Ginseng Is 39th of 50
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SK-II Facial Treatment Essence Review (2026): Is Pitera Worth It? We Compared Sulwhasoo and 12 Cheaper Essences
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Laneige Lip Mask Review (2026): Is It Worth It? We Checked 16 Lip Balms’ Ingredients
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Best Korean Sunscreen (2026): We Checked 20 Best Sellers’ UV Filters
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Best Glass Air Fryer (2026): We Checked 14 Models for What Touches Your Food
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Best Non-Toxic Air Fryer (2026): We Checked 25 Best Sellers for PFAS Claims
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Best Non-Toxic Cookware (2026): We Checked 25 Best-Selling Pans for PFAS Claims
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Beef Tallow for Skin: Benefits, Risks and What Science Says
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Magnesium Glycinate vs Citrate: Which Should You Take? (2026)
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Best Oil for Frying: Healthiest Picks for Deep and Pan Frying
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Is Beef Tallow Healthy? What the Science Says for Cooking (2026)
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Magnesium for Sleep: Does It Work, and Is Glycinate Best? (2026)
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Best Creatine Gummies (2026): Which Creatine Monohydrate Gummies Passed Lab Tests?
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Is Celsius Bad for You? We Checked the Label, the Studies and the Lawsuits
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Healthiest Energy Drinks (2026): 19 Cans Scored on Caffeine & Sugar
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Is Prime Healthy? We Dug Into the Label, the Lawsuits and the 200mg Can
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Best Creatine for Women 2026: Many Gummies Failed Lab Tests
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Best Protein Powder Without Lead or Heavy Metals (2026)
Go deeper.
The Wearable Scam Bible and The Supplement Scam Bible go further than any single article. $19 each.
