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L-Arginine for Endothelial Dysfunction

C Some Evidence Limited evidence from small studies, but some positive signals exist.

Research suggests improvement in FMD and blood pressure. However, the VINTAGE MI trial showed potential harm in acute MI patients. Generally considered safe in stable patients, but should be avoided post-MI.

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The Bottom Line

            
            
Research suggests improvement in FMD and blood pressure. However, the VINTAGE MI trial showed potential harm in acute MI patients. Generally considered safe in stable patients, but should be avoided post-MI.

            
            
        

    










    

  
Key Study Findings





    

        
        

            

                
                    animal_study
                
                
                
                
            

            
                Standardized root extract of Withania somnifera and Withanolide A exert moderate vasorelaxant effect in the …
            
            

                
                Dose: NMITLI-118R (Withania somnifera standardized root extract) and Withanolide A (WA)
                
                
                vs: Placebo
                
                
                
                Effect: NM and WA exerted moderate vasorelaxant effect (less than ACh); augmented ACh-induced relaxation; in
                
                
                not_reported
                
            

            
        

        
    







    
    

        
        

            

  
Key Statistics





            


    

        
11

        
Studies

    

    

        
600

        
Participants

    

    

        
            
            ↑
            
        
        
Positive

    

    

        C

        
Grade

    




        


        
        
        

            

  
Referenced Papers





            

                
                

                    

                        
                            Standardized root extract of Withania somnifera and Withanolide A exert moderate vasorelaxant effect in the rat aortic rings by enhancing …
                        
                        
                            
                                Other
                            
                            
                            
                        
                    

                    

                        Journal of ethnopharmacology
                        2021
                        
                        18 citations
                        
                    

                

                
            

        

        

        
        
        

            

  
Dosage & Usage





            
mg = milligrams · mcg = micrograms (1,000× smaller) · IU = International Units


            
            

                
Commonly Used Dosages

                

                    
                    

                        
endothelialfunction:

                        
3,000-6,000 mg/day

                    

                    
                    

                        
bloodpressuresupport:

                        
6,000-10,000 mg/day divided BID-TID

                    

                    
                

                
                

                    Upper limit: Not formally established; GI discomfort common above 10,000 mg/day
                

                
            

            

            
            

                
Dosages Studied in Research

                

                    

                        
                            

                                Dosage
                                Duration
                                Effect
                                N
                            

                        
                        
                            
                            

                                NMITLI-118R (Withania somnifera standardized root extract) and Withanolide A (WA)
                                --
                                
                                    
                                    Positive
                                    
                                
                                --
                            

                            
                        
                    

                

            

            

            
            

                Best taken: On empty stomach for best absorption; divide doses throughout the day
            

            
        

        

        
        
        

            

  
Safety & Side Effects





            

                
                

                    
Reported Side Effects

                    
    
                        
                        
  • 
                            ⚠
                            Gastrointestinal discomfort (nausea, diarrhea, bloating)
                        
    • 
                        
                        
  • 
                            ⚠
                            Hypotension at high doses
                        
    • 
                        
                        
  • 
                            ⚠
                            Worsening of herpes simplex (arginine promotes viral replication)
                        
    • 
                        
                        
  • 
                            ⚠
                            Potential harm in acute post-MI patients (VINTAGE MI concern)
                        
    • 
                        
                    

                

                

                
                

                    
Known Interactions

                    
    
                        
                        
  • 
                            ●
                            Antihypertensives (additive blood pressure lowering)
                        
    • 
                        
                        
  • 
                            ●
                            PDE5 inhibitors (sildenafil — excessive vasodilation risk)
                        
    • 
                        
                        
  • 
                            ●
                            Nitrates (excessive vasodilation risk)
                        
    • 
                        
                        
  • 
                            ●
                            Anticoagulants (may have mild antiplatelet effect)
                        
    • 
                        
                        
  • 
                            ●
                            Potassium-sparing diuretics (arginine may increase potassium levels)
                        
    • 
                        
                    

                

                

                
                

                    

                        Tolerable upper intake: Not formally established; GI discomfort common above 10,000 mg/day
                    

                

                
            

            

                Always consult your healthcare provider before starting any supplement.
            

        

        

        
        
        

            

  
Frequently Asked Questions





            




    
    

        
            Does L-Arginine help with Endothelial Dysfunction?
            
        
        

            Based on 11 studies with 600 participants, there is limited but promising evidence that L-Arginine may support Endothelial Dysfunction management. Our evidence grade is C (Some Evidence).
        

    

    
    

        
            How much L-Arginine should I take for Endothelial Dysfunction?
            
        
        

            Studies have used various dosages. A commonly studied range is 3,000-6,000 mg/day. Always consult your healthcare provider before starting any supplement regimen.
        

    

    
    

        
            Are there side effects of L-Arginine?
            
        
        

            Reported side effects may include Gastrointestinal discomfort (nausea, diarrhea, bloating), Hypotension at high doses, Worsening of herpes simplex (arginine promotes viral replication), Potential harm in acute post-MI patients (VINTAGE MI concern). Most side effects are mild and dose-dependent. Consult your doctor if you experience any adverse reactions.
        

    

    
    

        
            How strong is the evidence for L-Arginine and Endothelial Dysfunction?
            
        
        

            We rate the evidence as Grade C (Some Evidence). This rating is based on 11 peer-reviewed studies with 600 total participants. The overall direction of effect is positive.
        

    

    




        

        

        
        
        

            

  




            

                
                

                    
Other ingredients for Endothelial Dysfunction

                    

                        
                        
                            Cocoa Flavanols
                            A

                        
                        
                        
                            Grape Seed Extract
                            C

                        
                        
                        
                            Astaxanthin
                            D

                        
                        
                    

                

                

                
                

                    
L-Arginine for other conditions

                    

                        
                        
                            Heart Failure
                            D

                        
                        
                    

                

                
            

        

        

    


    
    






  
References

  
    
    
    
  1. 
      [1]
      Priya Pathak et al..
      J Ethnopharmacol.
      2021.
      Standardized root extract of Withania somnifera and Withanolide A exert moderate vasorelaxant effect in the rat aortic rings by enhancing …
      doi:10.1016/j.jep.2021.114296
      PubMed
    
    2. 
    
  















    

        FDA Disclaimer:
        These statements have not been evaluated by the Food and Drug Administration. The products and information on this website are not intended to diagnose, treat, cure, or prevent any disease. The evidence grades presented are based on our analysis of published peer-reviewed research and do not constitute medical advice. Always consult your healthcare provider before starting any supplement regimen.