When stress and depression hit, BDNF levels often drop leaving brain cells weaker and less able to connect
However, B12 injections are not a treatment for insomnia, depression, or anxiety on their own
Genetic variation in DPP4 (the gene encoding DPP-4) alters enzyme activity by up to 30% across populations, as shown in a study of 1,200 healthy volunteers published in the European Journal of Clinical Pharmacology
Pre-existing inborn errors of sulfur-amino-acid metabolism (e.g., homocystinuria) represent an absolute contraindication because parenteral methionine can exacerbate elevated homocysteine concentrations and associated thrombotic risk
The commonly recommended timing, morning on an empty stomach 30-60 minutes before eating, maximizes fat oxidation effects but may increase nausea in sensitive individuals