What are the side effects of Arginine?

Users most often report drowsiness, cold sores, fever blisters, diarrhea, acne. Side effects came up 8 times across 70 reports.

User reports can't establish safety. PubMed lists 585 meta-analyses and 1,869 randomized trials. Talk to a doctor or pharmacist, especially if you take other medication.

Arginine side effects

Across 70 first-hand reports, people mentioned a side effect 8 times (about 11 per 100 reports). The most common: drowsiness, cold sores, fever blisters. User reports show what people notice — they can't tell you whether Arginine is safe for you.

Reported side effects

drowsiness1

cold sores1

fever blisters1

diarrhea1

acne1

stomach issues1

gastrointestinal distress1

shingles reactivation1

In their own words

“I worked out for 6 days straight...took my Arginine & Citrulline...reactivated my shingles (which are painful AF)”

Didn't helpRead the discussion ↗

“You could take stuff like arginine and other NO enhancers for a better pump, but I don't think that will make a difference for gains.”

Didn't helpRead the discussion ↗

“I've tried L-theanine, magnesium glycinate, turmeric, arginine...which have provided no results or transient results”

Didn't helpRead the discussion ↗

“arginine had on me personally...I'd have the most utterly ridiculous skin-splitting pumps ever...it also vastly improved the quality of my erections...Arginine also stimulated acne production”

MixedRead the discussion ↗

“Arginine/Lysine: Took me out for the afternoon, slept.”

Didn't helpRead the discussion ↗

“Arginine is great for working out. But arginine also raised my blood pressure and now I know why I got these ugly cold sore blister things.”

MixedRead the discussion ↗

Is Arginine safe? What the research covers

AResearch: Strong585 meta-analyses · 1,869 randomized trials on PubMed

Cochrane Database Syst Rev · 2024

Nutritional interventions for preventing and treating pressure ulcers

Conclusion: The benefits of nutritional interventions with various compositions for pressure ulcer prevention and treatment are uncertain. There may be little or no difference compared to standard nutrition or placebo. Nutritional supplements may not increase gastrointestinal side effects, but the evidence is very uncertain. Larger studies with similar nutrient compositions would reduce these uncertainties. No study investigated the effects of special diets (e.g. protein-enriched diet, vegetarian diet) on pressure ulcer incidence and healing.