What is the result of applying too much product to hair?

When too much product is applied to hair, the most significant result is product buildup and greasiness. This occurs because excess product can accumulate on the hair strands and the scalp, leading to a dull, heavy appearance. The buildup can prevent the hair from receiving essential moisture and can inhibit its natural movement and shine. It also makes the hair feel greasy and weighed down, often necessitating extra cleansing to remove the residue.

In contrast, the other options suggest benefits that would not realistically result from an overapplication of product. Increased shine, enhanced volume, and improved hydration are desirable outcomes typically associated with proper product use in moderation. However, when too much product is used, these positive effects are overshadowed by the negative consequences of excess buildup.