5 Science-Backed Supplements I Take Every Day
Disclaimer: Not Medical Advice. Opinions are my own.
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Today's Newsletter at a Glance:
- My Supplement Framework
- 5 Supplements I Take Daily
- The Bottom Line
The supplement space is the Wild West.
There's so much confusion out there that it's hard to tell what’s marketing hype and what’s evidence-backed.
Supplements are not a substitute for any of the lifestyle pillars: movement, nutrition, recovery, and relationships.
Supplements may give you an extra edge once you are checking these boxes.
In today's newsletter, I'll share five science-backed supplements that I take daily (I'll include my partner links to the ones I take).
Disclaimer: This newsletter is for education, not medical advice. These are supplements, not medications. Don’t use them to replace, stop, or change any prescription. Talk to your doctor before starting any new supplement, especially if you take medications or have a chronic condition.
Creatine Monohydrate
Creatine is one of the most studied supplements on the market.
If I could only recommend one supplement, this would be it.
If you strength train, or you're getting older and want to prioritize your muscle, creatine is the easiest yes on this list.
What it does in your body. Your cells run on ATP.
During short, intense effort, ATP gets used up in seconds.
Creatine is stored mostly in muscle, much of it as phosphocreatine, which rapidly hands a phosphate back to regenerate ATP. More stored creatine means more fuel for that next rep, sprint, or stair climb.
Your brain uses the same system, which is why researchers have started looking at cognition.
What the evidence shows.
Women benefit too. Women start with lower creatine stores, and early data point to gains in strength, mood, and cognition, especially when sleep-deprived.
What to be aware of.
- It raises your creatinine. Creatine breaks down into creatinine, the lab marker used to estimate kidney function. Your number may tick up, which can look like kidney trouble when it isn't. Tell your doctor you take it and ask for an eGFR based on cystatin C alone (eGFRcys). If you already have kidney disease, creatine should probably be avoided.
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Expect to gain 1–3 pounds on the scale. That’s water pulled into muscle, not fat.
- The hair loss myth. It traces back to a single small 2009 study measuring a hormone, not hair. It hasn't held up. Read more here.
Dosing. 3–5 grams of creatine monohydrate daily, every day, at any time of day. No loading phase needed; you'll saturate your muscles within about 3–4 weeks. Mix it into water, coffee, or a smoothie.
The creatine I take daily.
Omega-3 (EPA/DHA)
When people think of heart-health supplements, omega-3s are near the top of the list.
What they do in your body. EPA and DHA are long-chain omega-3 fats. Your body uses them to build the membranes of your heart, brain, and red blood cells. They can lower triglycerides by reducing the amount of fat your liver packages and sends into the blood. They also serve as raw material for compounds that have been shown to reduce full-body inflammation. DHA is a major structural fat in the brain and retina.
What the evidence shows.
- 28% fewer heart attacks at just 1 gram a day. The VITAL trial followed nearly 26,000 adults for more than five years. Omega-3s didn't reduce its main combined cardiovascular endpoint, but total heart attacks fell.
- Triglycerides down 30% or more. The American Heart Association's science advisory concludes that 4 grams a day of prescription omega-3s lowers very high triglycerides by at least 30%.
If you rarely eat fatty fish, an omega‑3 may be a reasonable way to increase EPA and DHA intake, but higher doses deserve a clinician’s input.
What to be aware of.
- Atrial fibrillation. This is the one I want you to know about. Higher doses are mainly for lowering high triglycerides, and AFib risk rises with dose (most clearly above 1.5 g/day in people at high cardiovascular risk), so only go higher with your doctor's input.
- Blood thinners. At normal doses, bleeding risk is small, but if you're on an anticoagulant or antiplatelet drug, loop in your doctor.
- Freshness matters. Fish oil oxidizes. A strong fishy smell is a bad sign. Look for third-party testing and store it in the fridge.
Dosing. For general health, about 1 gram of combined EPA+DHA daily, taken with a meal that contains fat.
To see where you stand, ask for an Omega-3 Index blood test; most experts target 8% or higher.
The omega-3 I take daily.
Vitamin D3 + K2
Vitamin D and K2 are often paired. Vitamin D increases calcium absorption, while vitamin K activates proteins involved in bone mineralization and regulates abnormal vascular calcification.
What they do in your body. Vitamin D3 is technically a hormone precursor. Your liver and kidneys convert it to its active form, which increases calcium absorption from your gut and supports bone, muscle, and immune function.
Vitamin K helps activate two proteins: osteocalcin, which supports bone mineralization, and matrix Gla protein (MGP), which helps inhibit abnormal calcium buildup in artery walls.
What the evidence shows.
What to be aware of.
- Get your vitamin D level tested. Ask for a 25-hydroxy vitamin D blood test. It's cheap and tells you whether you need this at all and how much.
- More is not better. Vitamin D is fat-soluble and builds up. Very high doses over time can push calcium too high and cause kidney stones. Don't take more than 4,000 IU daily unless your doctor has you on a specific plan.
- Warfarin users: stop and ask. Vitamin K directly counteracts warfarin (Coumadin). Do not start K2 without your prescriber. Newer blood thinners like apixaban (Eliquis) don't work through vitamin K, but tell your doctor anyway.
- Take it with food. Both are fat-soluble and absorb better with a fatty meal.
Dosing. For most adults, 1,000–2,000 IU of vitamin D3 daily, adjusted based on your blood level. A reasonable target is 30–50 ng/mL. Pair it with 90–200 mcg of vitamin K2 in the MK-7 form. Many products combine them. Recheck your level after about three months.
The vitamin D3 + K2 I take daily.
Magnesium Glycinate
Magnesium glycinate has worked best for me as a sleep supplement.
Many people fall short on magnesium. Processed food strips it out, and many people don’t eat enough leafy greens, nuts, seeds, beans, and whole grains.
What it does in your body. Magnesium is a cofactor for more than 300 enzymes. It helps to make and use ATP, relax muscles after they contract, regulate nerve signaling, and keep your heart's electrical rhythm steady. It also plays a role in blood pressure and in how your cells respond to insulin. The glycinate form binds magnesium to the amino acid glycine, which is well absorbed and gentle on the gut. Glycine itself has a mild calming effect, which is part of why this form is popular at bedtime.
What the evidence shows.
What to be aware of.
- Medication timing. Magnesium can block absorption of certain antibiotics (tetracyclines and fluoroquinolones like ciprofloxacin), thyroid medication, and osteoporosis drugs. Separate them by at least 2–4 hours.
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Kidney disease. Your kidneys remove excess magnesium. If your kidney function is reduced, it can build up, so talk to your doctor before taking it.
Dosing. 200–350 mg of elemental magnesium daily, taken in the evening. Start low and work up. Food should still be your base: pumpkin seeds, almonds, spinach, black beans, and dark chocolate are all excellent sources.
The magnesium glycinate I take daily.
Berberine
You've probably seen berberine called "nature's Ozempic." That's an overstatement.
But it is one of the few plant compounds with real, measurable effects on blood sugar and cholesterol, which is why it makes this list.
What it does in your body. Berberine is a compound found in plants like goldenseal and barberry. It activates AMPK, an enzyme that acts like your cells' fuel gauge. That tells your liver to make less glucose and helps your muscles take up more. Berberine also increases the number of LDL receptors on your liver, the same basic target statins work through, which pulls more LDL out of your blood. It also changes your gut bacteria, which may explain part of its effect.
What the evidence shows.
- HbA1c drops by 0.4%-1%. In a 12-week randomized controlled trial of 409 participants, HbA1c fell 0.99% with berberine. In placebo-controlled trials, berberine lowers HbA1c by about 0.4–1%, with bigger effects in people whose glucose starts higher.
- Lowered ApoB and Lp(a), with bigger drops in women. In a 2026 randomized trial in Hong Kong, 100 Chinese women with high cholesterol took 500 mg of berberine twice daily or placebo for 12 weeks. ApoB fell about 13 mg/dL versus placebo, and LDL, triglycerides, and Lp(a) dropped too. In a matched trial in men, ApoB fell less, and LDL and Lp(a) didn’t fall significantly. One caution: 16% of women on berberine dropped out, mostly for stomach side effects, versus 4% on placebo.
- LDL down about 19 mg/dL, triglycerides down about 33 mg/dL. A 2025 meta-analysis of placebo-controlled trials also found fasting glucose about 9 mg/dL lower and waist size about 3 cm smaller. Real numbers, but a long way from "nature's Ozempic."
- The gap: We don't have long-term outcome trials showing berberine prevents heart attacks or diabetes complications.
What to be aware of.
- It interacts with medications. Berberine affects the liver enzymes that clear many common drugs, including some statins, blood thinners, and transplant drugs. If you take any prescription medications, check with your doctor.
- Low blood sugar risk. Combined with metformin, insulin, or other diabetes medications, it can push glucose too low. Don't stack it on your own.
- Not in pregnancy or breastfeeding. Berberine can cross the placenta and pass into breast milk, and it can raise bilirubin levels in newborns, which can be dangerous.
- It's not a substitute. If you need medications, berberine is not a swap.
- Quality varies. Buy third-party tested products.
Dosing. 500 mg two to three times daily with meals, for a total of 1,000–1,500 mg. It's absorbed poorly and clears quickly, so splitting the dose matters. Start with 500 mg once a day for a week to let your gut adjust.
The berberine I take daily.
The Bottom Line
No supplement outworks a bad lifestyle.
Dial in your movement, nutrition, recovery, and relationships.
Supplements may be able to give you an added edge.
How to buy smart. What's on the label isn't always what's in the bottle. Look for third-party seals from USP, NSF, or Informed Choice, and skip proprietary blends that hide the doses.
How to know it's working. Get your bloodwork. Check your vitamin D, lipids (including ApoB), glucose, and HbA1c before and a few months after.
Data beats guessing.
Reply to this newsletter:
Do you already take any supplements on this list?
(Respond directly to this email. I read all responses)
Only the best,
Jeremy London, MD
P.S. Don't forget to follow my podcast for free on Spotify or Apple Podcasts
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* Disclaimer: This blog is for general informational purposes only and does not constitute the practice of medicine, nursing, or other professional health care services, including the giving of medical advice, and no doctor/patient relationship is formed. The use of information on this blog or materials linked from this blog is at the user’s own risk. The content of this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users should not disregard or delay seeking medical advice for any medical condition they may have and should consult their healthcare professionals for any such conditions.
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