Do you remember in Jurassic Park, when they explained The Lysine Contingency? Basically, the dinosaurs were genetically engineered to be unable to produce the essential amino acid, Lysine. That way, without the humans to supplement their diet with it, they would die.
Something about these boosters made me think of it…
Good sources of lysine include foods that are rich in protein, such as: Meat, specifically red meat, pork, and poultry. Cheese, particularly parmesan. Certain fish, such as cod and sardines. Eggs. Soybeans, particularly tofu, isolated soy protein, and defatted soybean flour. Spirulina. Fenugreek seed.