adding serums during microneedling isnt purely an upsell, there is a legitimate reason behind it though the extent of benefit can vary depending on what product is used. the micro channels created during the treatment temporarily increase how deeply certain topical ingredients can penetrate the skin, so applying something like hyaluronic acid or growth factor serums right after can enhance hydration and support the healing process. that said not every added product is worth the extra cost, and some providers do market add ons more aggressively than others, so its reasonable to ask your provider specifically what theyre applying and why before agreeing to any extras