CitraNOX by Ortho Molecular Products

If your home blood pressure readings run high-normal or elevated and you want a non-drug nudge, a nitric oxide supplement built around L-citrulline is worth a trial. It also fits endurance and strength athletes chasing better blood flow during training, and adults with cold hands and feet from sluggish circulation. If your hs-CRP (an inflammation marker) trends high, the quercetin and grape seed extract here add modest anti-inflammatory and vessel-calming effects. If you already have low blood pressure, this isn’t the right pick.

L-citrulline converts in your kidneys to L-arginine, which your blood vessel lining uses to make nitric oxide (the gas that tells arteries to relax). Citrulline raises blood levels of arginine more reliably than taking arginine itself, because it skips gut and liver breakdown. Grape seed extract polyphenols protect nitric oxide by reducing oxidative stress, and quercetin nudges the same pathway while modestly lowering hs-CRP in some people. In studies, this trio often trims systolic and diastolic blood pressure by about 3–5 mmHg within 4 to 8 weeks and can make exercise feel easier at a given pace.

Use the 4-capsule daily dose as directed. For blood pressure, take it consistently at the same time each day; splitting morning and evening is reasonable. For training, take the full dose 60–90 minutes before workouts. Food is optional, though many prefer it with a small meal to avoid mild stomach upset. If you combine with beetroot or other nitrate-rich products, start lower and assess blood pressure response.

Skip combining with prescription nitrates like nitroglycerin or isosorbide, or with erectile dysfunction drugs such as sildenafil, without clinician guidance, since blood pressure can drop too far. If you take antihypertensive medications, monitor home readings when you start. Grape seed extract and quercetin have mild antiplatelet effects, so use caution with warfarin, apixaban, rivaroxaban, clopidogrel, or aspirin and discuss with your prescriber.

Avoid if your baseline blood pressure is low, you get lightheaded when standing, or you’ve had recent fainting. Pregnancy and breastfeeding: data are limited, so skip unless your clinician advises. Allergic to grapes, grape seed, or wine extracts, avoid. If you’re scheduled for surgery or have a bleeding disorder, check with your surgeon due to the grape seed and quercetin components.