Our catalog tracks 66 supplements, and behind each one sits a list of medications it can interfere with. Add them up and you get 108 supplement-drug pairs worth knowing about.
We pulled the data apart to see where the risk actually concentrates. A few patterns stand out, and one drug class dominates everything else.
The numbers first
54 of the 66 supplements in our catalog interact with at least one medication class. That's not a scare statistic; most of these interactions are mild, and timing or dose awareness handles them.
But the distribution is lopsided. A handful of drug classes account for most of the pairs, which means a few questions cover most of the risk.
- Blood thinners: 19 supplements
- Diabetes medication: 9 supplements
- Blood pressure medication: 7 supplements
- Immunosuppressants: 5 supplements
- Antibiotics: bind to magnesium, zinc, calcium, and iron
Blood thinners are the minefield
19 supplements in the catalog interact with anticoagulants, by far the biggest cluster. Some are obvious, like omega-3s and vitamin E. Others surprise people: quercetin, MSM, glucosamine, resveratrol, NAC, even aged garlic extract.
The mechanism varies, but the theme is the same: added bleeding risk on top of a drug that already thins your blood. Vitamin K2 is the special case, since it directly opposes warfarin rather than adding to it.
If you take any anticoagulant, the rule is simple. Nothing new enters your stack without your doctor seeing the full list.
Glucose-lowering stacks on glucose-lowering drugs
9 supplements push blood sugar in the same direction as diabetes medication: berberine, alpha-lipoic acid, fenugreek, black seed oil, and psyllium among them.
Each alone is modest. Combined with metformin or insulin, the additive effect is a real hypoglycemia risk. The rule for medicated users is one addition at a time, with a glucose meter nearby.
The quiet ones people miss
Levothyroxine is the classic. Iron and calcium both block its absorption, so thyroid medication needs a 2 hour window away from mineral supplements. It rarely comes up at the pharmacy counter.
Antibiotics have the same problem: tetracyclines and quinolones bind to magnesium, zinc, calcium, and iron, and absorb worse for it. During a course of antibiotics, minerals move to a different part of the day.
And biotin doesn't interact with a drug at all. It interferes with lab tests, including thyroid and troponin panels, so high doses should stop 48 to 72 hours before blood work.
What to actually do with this
Severity matters more than count. Most of the 108 pairs are graded mild, a caution about absorption or timing rather than danger. A small set, like red yeast rice with statins or K2 with warfarin, are hard stops.
The practical filter is one question: do you take any prescription daily? If no, interactions mostly reduce to timing between supplements. If yes, your supplement list and your prescription list need to meet each other once, in front of a professional.
This is also the check Suplagen runs automatically when you build a stack, against this same data.
General information, not medical advice. Talk to a clinician before starting a new supplement, especially if you take medication or are pregnant or nursing.
Skip the research phase.
Answer a few questions and Suplagen builds your stack: doses, timing, and safety checks included. Free on iPhone.