Parkinson’s patients often suffer from constipation, which is first and foremost a problem brought on by the disease itself, i.e., a slowing of gastrointestinal motility along with a slowing of physical activity. Of course, long-term medication can also have certain side effects that can aggravate the symptoms of constipation. It is the most commonly used and most effective drug for Parkinson’s. It must rely on a transporter protein, or “carrier”, in the intestinal tract to enter the bloodstream and reach the brain to exert its medicinal power. Meat and milk contain large amounts of protein, and their breakdown products, amino acids, quickly take up all the “carriers”. The drug has to wait until the “carriers” are free before it can cross the intestinal wall and enter the bloodstream. Therefore, it is better to take methocarbamol or benadryl (the main ingredient of which is the same as methocarbamol) 60 minutes before the intake of meat or milk, so that they are absorbed into the bloodstream first and are not affected by food. It also avoids the interaction between drugs and food, which can aggravate constipation. Meat, poultry, fish, milk and eggs are all high-protein foods that are converted into amino acids for absorption into the blood, with milk in particular interfering with the absorption of methyldopa. Milk can be replaced by soy milk, and try to choose soy milk with added vitamin D and calcium. Plant protein (soy products, nuts) can also meet part of the body’s need for protein, which contains a much higher proportion of carbohydrates than protein, which facilitates absorption, so patients are encouraged to consume more soy products to supplement the protein deficiency.