OrthoMune® by Ortho Molecular Products

NAC and quercetin are most useful when your sick-day risk spikes: winter, air travel, teaching, parenting young kids, or heavy training blocks. This blend also fits adults whose Vitamin D, 25-Hydroxy is in the lower part of the normal range and who want a daily immune support supplement that includes vitamin D3 and zinc. If you rarely eat zinc-rich foods or keep getting upper‑respiratory infections, a combined formula is more practical than juggling five bottles. If your vitamin D is meaningfully low, you’ll likely need a separate higher-dose D3 for repletion first.

N-acetyl-L-cysteine (NAC) helps your body make glutathione, the cell’s main antioxidant, and it thins mucus in the airways. Quercetin acts as a zinc “shuttle,” helping zinc get into cells where it affects viral replication steps, and it calms mast cells (the cells behind sneeze/itch cascades). Vitamin C supports white blood cell function and recycles antioxidants. Vitamin D3 tunes innate defenses, and zinc is required for normal T-cell and neutrophil activity. In practice, mucus changes are felt within days; steadier immune effects build over 4–8 weeks. Inflammation markers like hs-CRP sometimes fall modestly in responders.

Take 2 capsules daily with food, ideally breakfast, to prevent zinc-related nausea. You can split the dose morning and evening if you prefer. Quercetin (dihydrate) absorbs better with a meal containing fat. This is a daily maintenance dose: NAC 600 mg, quercetin 250 mg, vitamin C 600 mg, vitamin D3 2,500 IU, and zinc 25 mg. If your Vitamin D, 25-Hydroxy is low, pair with a separate higher-dose D3 short term under clinician guidance.

Space zinc 2–4 hours from levothyroxine and from tetracycline or fluoroquinolone antibiotics to avoid absorption interference. NAC can amplify nitroglycerin’s effects and headaches; don’t combine without clinician input. If you form calcium oxalate kidney stones, be cautious with higher-dose vitamin C. Avoid extra D3 if you have a history of high calcium, sarcoidosis (a granulomatous condition that raises vitamin D activity), or recurrent kidney stones. Long-term zinc at 25 mg daily can lower copper; consider checking Copper if using for many months.