There is limited evidence on the effect of whey protein on cholesterol levels. Some studies suggest that consuming whey protein may have a positive impact on cholesterol levels, while others have found no significant effects.
One study published in the "American Journal of Clinical Nutrition" in 2006 found that consuming whey protein for 12 weeks significantly improved the lipid profile in overweight and obese individuals, including reducing total cholesterol and LDL (bad) cholesterol levels.
However, a review article published in the "European Journal of Clinical Nutrition" in 2018 found that while some studies have reported a positive effect of whey protein on cholesterol levels, others have found no significant effects. The authors concluded that more research is needed to determine the effects of whey protein on cholesterol levels.