This online intervention offer provides anonymous, free-of-charge professional support to NPS-consuming youth by providing NPS-related information, a validated self-assessment test, an online diary, and three 30-day intervention modules (‘Brief Intervention’, Safer Use’, and ‘Quit or Reduce’). The intervention programme will be operated for (at least) the next 5 months by trained prevention experts, and is available in 10 languages (DE, FI, FR, GR, IT, LV, NL, PT, SI, SK) in 13 EU countries: Austria, Belgium, Cyprus, Finland, Germany, Greece, Italy, Latvia, Luxembourg, The Netherlands, Portugal, Slovakia, and Slovenia.