More people are injecting illegal drugs than previously thought, says a United Nations report on worldwide drug use.
In all, 13.2 million people injected drugs in 2021, 18% more than previously estimated, said the Vienna-based UN Office on Drugs and Crime (UNODC).
Synthetic substances such as fentanyl and methamphetamine now dominate the illegal drug markets, the UN says.
Globally, drug users increased by 23% and drug-related disorders were up by 45% in a decade to nearly 40 million.
People with mental health disorders, those from lower socio-economic backgrounds and young people were most vulnerable, the report said.
Eastern Europe and North America were found to have a higher prevalence of people injecting drugs than in East and South-East Asia.
Fentanyl has altered the opioid market in North America with deadly consequences, the report found.
On the basis of data from 18 countries, it said men were five times more likely than women to inject drugs and introduce their female partners to the habit.
Still, only one in five people can access treatment, says the UN, with women in particular facing barriers.
The reasons are many and intertwined: Covid-19, but also fear of legal sanctions, social stigma, lack of childcare and fear of losing custody of their children.
Ghada Waly, head of the UNODC, said that in many instances, treatment was failing those who need it.
“We need to step up responses against drug-trafficking rings that are exploiting conflicts and global crises to expand illicit drug cultivation and production, especially of synthetic drugs, fuelling illicit markets and causing greater harm to people and communities,” Ms Waly said.