Whey protein is a popular supplement among athletes and fitness enthusiasts for its potential benefits in muscle growth, recovery, and weight loss. It is derived from the liquid part of milk during cheese production and is available in different forms, such as whey protein concentrate and whey protein isolate. Generally, whey protein is considered safe for most people when used as directed. However, there are some potential side effects and concerns to be aware of. Some individuals may experience digestive issues, such as bloating, gas, and diarrhea, particularly if they are lactose intolerant. People with a cow's milk allergy should avoid whey protein as it can trigger allergic reactions. There have been concerns about the impact of high protein intake on kidney and liver health, but current evidence suggests that it is unlikely to cause harm in healthy individuals. Those with existing kidney or liver conditions should consult their doctor before using whey protein supplements. Some early studies suggested that high protein intake might lead to osteoporosis, but more recent research indicates that it may actually be beneficial for bone health. As with any supplement, it is advisable to talk to a healthcare professional before starting whey protein to ensure it is suitable for your individual health needs.