- Because growth hormone depletes potassium and opposes the actions of insulin, diabetics and borderline diabetics should only use GH releasers under a physician’s supervision. L-Arginine and L-ornithine may improve or worsen diabetic conditions.

- L Arginine and L-ornithine sometimes have the side effect of reactivating latent herpes virus infections. Therefore persons who have ever had ocular or brain herpes should not use these amino acids and therefore avoiding any potential side effects..

-Those with certain psychoses may experience worsened symptoms if they take L-arginine or L-ornithine.

Cancer patients should avoid taking L Tyrosine, as certain cancers, such as melanoma, can depend on this amino acids to fuel their growth. Persons taking antidepressant drugs should consult their doctor before taking L-tyrosine supplementation; as it may be necessary to adjust antidepressant dosages due to the mood enhancing effects of L-tyrosine.  Supplemental use of L-tyrosine may raise or normalize blood pressure.  Insomnia may occur from over stimulation if taken too close to bedtime.