L-arginine for fertility

On this page

1. What is L-arginine?
2. Function and how it works
3. Fertility benefits
4. Recommended daily dose
5. Food sources
6. Cautions and contraindications
7. My Fertility Guide
8. Related pages

1. What is L-arginine?

L-arginine is a semi-essential amino acid that the body uses to produce nitric oxide (NO), a key signalling molecule that relaxes blood vessels and improves blood flow. Adequate L-arginine is essential for normal circulation, immune function, wound healing and reproductive function. While the body can produce some L-arginine, dietary or supplemental intake becomes important during periods of high demand — including preconception.

Reference ranges and recommended intakes vary from country to country — always interpret guidance against the recommendations of your own healthcare authority.

2. Function and how it works

L-arginine supports fertility through:

1. Nitric oxide production. NO dilates blood vessels, increasing blood flow to ovaries, uterus and testes.
2. Endometrial thickness. Improved uterine blood flow supports a thicker, more receptive endometrium.
3. Follicle development. Better ovarian blood flow improves follicle and oocyte quality.
4. Sperm parameters. L-arginine is a precursor to spermidine and spermine, polyamines essential for sperm production and motility.
5. Erectile function. NO is the key vasodilator responsible for normal erectile function.

3. Fertility benefits

L-arginine is particularly useful for:

1. Women with thin endometrial lining
2. Women with poor ovarian blood flow on Doppler ultrasound
3. Couples preparing for IVF or IUI
4. Men with low sperm count, poor motility or erectile difficulties
5. Recurrent implantation failure

4. Recommended daily dose

I recommend a daily dose of 3–6 g of L-arginine, split into 2–3 doses on an empty stomach. For erectile function, doses of up to 5 g per day are often used. Combine with antioxidants (vitamin C, vitamin E, CoQ10) for best effect.

5. Food sources

L-arginine is found in:

1. Nuts (especially walnuts, almonds, peanuts)
2. Seeds (especially pumpkin and sesame)
3. Lean meat, poultry and fish
4. Dairy products
5. Lentils, chickpeas, soybeans

6. Cautions and contraindications

1. L-arginine can reactivate latent herpes simplex virus — avoid if you have a history of cold sores or genital herpes, or balance with lysine supplementation.
2. Avoid L-arginine if you have low blood pressure, take blood pressure or erectile dysfunction medications without medical supervision.
3. Avoid after a recent heart attack — some studies showed harm in this group.
4. Discontinue once pregnancy is confirmed unless advised otherwise by your doctor.
5. Always consult with a fertility specialist or your doctor before starting any new supplement regime.

7. My Fertility Guide

8. Related pages

• Fertility supplements directory
• Vitamin E
• Coenzyme Q10
• Vitamin C
• Thin endometrial lining
• Male infertility