L- arginine is sometimes suggested as a fertility supplement to help women get pregnant.

L-arginine is a naturally occurring amino acid necessary for protein synthesis. It is found in foods such as red meat, poultry, fish, nuts, seeds and dairy products. L-arginine is best known for its effects on the vascular system. The amino acid works through the nitrous oxide pathway to promote blood vessel dilation and improved blood flow. Oral L-arginine appears most beneficial in treating cardiovascular conditions such as:

  • Coronary heart disease
  • Congestive heart failure
  • Peripheral vascular disease

Side effects of oral L-arginine may include:

  • Abdominal pain
  • Bloating
  • Diarrhea
  • Gout
  • Airway inflammation
  • Exacerbation of asthma

Potential drug interactions with medications include antihypertensive drugs, nitrates (i.e. nitroglycerine) and Viagra-like medications.

Can L-arginine improve female fertility?

L-arginine has been proposed as possibly increasing blood flow to the uterus and ovaries. Unfortunately, there is little scientific evidence showing L-arginine to be beneficial for fertility.In 1999, an Italian group (Human Reproduction, Battaglia et al) reported that oral L-arginine (16 grams/day) supplementation – in poor responders to IVF treatment – may improve ovarian response, endometrial receptivity and pregnancy rates. Follicular fluid levels of L-arginine were found to be elevated in those patients receiving L-arginine supplementation. The same authors in 2002 reported that oral L-arginine (16 grams/day) supplementation in women undergoing IVF appeared to have detrimental consequences on embryo quality, implantation and pregnancy rates.A 2010 report by Bodis et al. (Human Reproduction) reported that elevated follicular fluid L-arginine was associated with fewer oocytes and embryos with a reduction in pregnancy rates. In this study, patients were not receiving any supplemental L-arginine.