Nitric Oxide Boosts, Best Supplements, Amino Acids, Protein (Ask Dr. Cohen #4)
Welcome to the Ask Dr. Cohen series, part #4. Got a question? Use this form to have your question answered next time.
Q: Can I take citrulline instead of beet juice for an NO boost (e.g., Swiss RX)?
Both paths can raise nitric oxide, but they work differently.
Beetroot / dietary nitrate uses the nitrate→nitrite→NO pathway (via oral bacteria). Meta-analyses and umbrella reviews report modest but significant ergogenic effects, especially for efforts ~2–10 minutes and some HI work (Senefeld 2020; Alsharif 2023; Silva 2022). Disrupting oral nitrate-reducers (e.g., antiseptic mouthwash) blunts this pathway and can raise BP (Bryan 2022; Morou-Bermúdez 2022; Blot 2021).
Citrulline raises arginine for endogenous NO synthesis (NOS pathway). Evidence is mixed: some reviews report small positive effects; others see no clear benefit depending on dose, duration, and outcome (Viribay 2022; Trexler 2019; Harnden 2023).
Bottom line: if you tolerate beets, nitrate sources have more consistent real-world data for certain performance windows; citrulline can still be useful, particularly in resistance contexts, but results vary by protocol.
What about Nitrosigine®?
Nitrosigine (inositol-stabilized arginine silicate) increases circulating arginine and has shown acute improvements in flow-mediated dilation and related endpoints in controlled studies (Rogers 2020; Kalman 2016; Kalman 2015). It targets the arginine/NOS pathway and can be paired with dietary nitrate for complementary mechanisms.
Q: Is FUNDAMINOS a complete protein support?
FUNDAMINOS provides essential amino acids (EAAs) for rapid, low-calorie support. For “complete” daily protein, we usually pair EAAs with collagen-rich protein to cover connective-tissue needs while keeping total leucine intake on point. See FUNDAMINOS and PURECLEAN PROTEIN.
Q: What do the Cohens take daily?
Foundational stack geared to mitochondrial function and NO support. Examples include PURECLEAN PROTEIN + CHOCOBERRY BLAST; FUNDAMINOS; adrenal salts (Na/K/C); magnesium forms; beef liver (trace minerals); sea veggies; cod liver oil brands that avoid synthetic A; Whole-C; Gamma-E; light (UVB/NIR) exposure; periodic blood donation for iron management; hypoxic training. Personalization is key.
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References
Dietary nitrate improves performance (systematic/meta): Senefeld 2020; Alsharif 2023; moderators & time-window: Silva 2022.
Beetroot/nitrate performance updates: Zoughaib 2024; umbrella/meta: Poon 2025.
Citrulline evidence (mixed): Viribay 2022; Trexler 2019; Harnden 2023; resistance context: Gonzalez 2023.
Nitrosigine® (inositol-stabilized arginine silicate): FMD/vasodilation Rogers 2020; cognitive/PK-PD Kalman 2016; safety/PK-PD Kalman 2015.
Oral microbiome & nitrate pathway (mouthwash blunts NO/BP): Bryan 2022; Morou-Bermúdez 2022; Blot 2021; microbiome shifts with nitrate: Moran 2024.