TL;DR:

Arginine doesn’t just boost nitric oxide (NO) for better circulation — it also increases human growth hormone (HGH), supporting lean muscle, fat metabolism, and immune function. Combining arginine with citrulline and ornithine amplifies both effects.

From Circulation to Hormones

Most people know that arginine helps your blood vessels relax by increasing nitric oxide (NO) — improving circulation and lowering blood pressure.
What’s less known is that arginine can also stimulate human growth hormone (HGH) — the hormone that helps your body repair, grow, and stay strong.

A classic study [1] found that arginine increases growth hormone by suppressing somatostatin, a hormone that normally blocks HGH release. Newer research also shows improved growth hormone production with arginine supplementation [2,3]. Dose matters; a dose of 5-9 g seemed to be appropriate in one study, increasing it to 13 g diminished results, possibly because the high dose caused GI distress in some of the subjects [4].

Benefits of Higher HGH Levels

Healthy levels of HGH contribute to:

  • Increased lean muscle mass
  • Enhanced fat metabolism and energy
  • Improved immune system function
  • Better thyroid conversion (T4 → T3)
  • Stronger bones
  • Support for healthy cholesterol levels

Interestingly, the combination of arginine and citrulline may help reduce cholesterol, as shown in research [5]).

Why Combination Formulas Work Best

A well-designed formula like Arginine Complex (Zorex) combines several amino acids for synergistic effects:

  • L-Arginine and L-Citrulline → boost nitric oxide and circulation
  • L-Ornithine → frees up more arginine for NO production and supports immune cells
  • L-Lysine → balances arginine absorption and strengthens antiviral defense

Together, these ingredients enhance nitric oxide production, increase HGH, and support immune performance — making them useful for:

  • Circulatory health (angina, male vitality)
  • Recovery and wound healing
  • Geriatric immune support
  • Reducing cholesterol
  • Supporting metabolic and thyroid balance

Takeaway

Arginine’s benefits extend beyond circulation — it also supports hormonal balance, energy, and repair. For many, adding citrulline and ornithine enhances both nitric oxide and growth hormone production naturally.

References:

  1. J Clin Endocrinol Metab 1988 Dec;67(6):1186-9. Arginine stimulates growth hormone secretion by suppressing endogenous somatostatin secretion
  2. Int J Endocrinol. 2022 Nov 23;2022:8739289. Growth Hormone Response to L-Arginine Alone and Combined with Different Doses of Growth Hormone-Releasing Hormone: A Systematic Review and Meta-Analysis
  3. Journal of Strength and Conditioning Research 24(4):p 1082-1090, April 2010. Increases Growth Hormone and Insulin-Like Growth Factor-1 Serum Levels After Heavy-Resistance Exercise in Strength-Trained Athletes
  4. Growth Hormone & IGF Research Volume 15, Issue 2, April 2005, Pages 136-139 Growth hormone responses to varying doses of oral arginine
  5. Proc Natl Acad Sci U S A. 2005 Sep 20;102(38):13681-6. l-Citrulline and l-arginine supplementation retards the progression of high-cholesterol-diet-induced atherosclerosis in rabbits