Weight gain and weight loss supplements generally offer limited effectiveness on their own. Weight gain formulas typically provide extra calories and protein, which can help if you struggle to eat enough, though they may cause mild bloating or digestive upset. Weight loss supplements often contain stimulants or fibre to temporarily reduce appetite, which can sometimes lead to mild jitteriness, sleep changes, or stomach discomfort. Neither supplement is a magic solution; sustainable results come from a balanced diet and exercise. Because these products can vary widely in ingredients, it is best to consult a doctor or dietitian to ensure they are safe for your individual health goals.