BACKGROUND: Mainstream social media platforms host public advertisements that connect drug sellers with potential buyers, but we are not aware of independent evidence on the performance of user-reporting systems relating to drug-selling content. We audited TikTok's response to reports of UK-facing drug-selling accounts.

METHODS: We purposively identified 455 public accounts advertising cocaine, synthetic-cannabinoid e-cigarette liquids or controlled medicines to UK users. Eligible accounts displayed an offer or route to supply. Accounts were reported through TikTok's regulated-goods pathway and revisited after 2, 7 and 14 days.

RESULTS: TikTok returned an explicit "no violation" decision for 95.2% of reports. After 14 days, 83.5% of accounts remained publicly accessible, with persistence across all three market categories.

CONCLUSIONS: TikTok's ordinary account-reporting pathway produced ineffective removal of the overt UK-facing drug-selling accounts examined in this audit. Most were classified as non-violating and remained publicly accessible two weeks after reporting. The consistency of this outcome across distinct drug markets indicates a cross-cutting weakness in the tested reactive moderation pathway and warrants examination of how reports are classified, escalated and acted upon.