Which current is known for softening sebum during iontophoresis?

The correct answer is galvanic current, which is specifically used in iontophoresis to soften sebum. Galvanic current is a direct current that flows in a single direction and is primarily employed in various aesthetic treatments because of its ability to facilitate the penetration of products into the skin. During iontophoresis, the use of this current allows positively charged ions in certain products to be pushed deeper into the skin, while also softening sebum and helping to clear clogged pores.

This method is particularly beneficial in treating different skin conditions such as acne, as it can enhance product efficacy and prepare the skin by making it more receptive to treatment. The softening action of the sebum with galvanic current aids in the extraction process, allowing for a better outcome when addressing skin impurities.