For former property agent Manimaran Murugayan, life begins anew at 40. After 20 years of abusing hard drugs, he decided this year - when he turned 40 - to clean up his act for good.

Mr Manimaran, a heroin addict from 1986 to 2001, started injecting a cocktail of Dormicum and Subutex into his thigh veins in 2002. Dormicum is a benzo- diazepine-based relaxant and Subutex, which is banned, is a buprenorphine-based painkiller which can give a high.

'All the veins in my arms have collapsed,' he said. 'After years of injecting Subutex and Dormicum in my right thigh, I got a huge blood clot there and had to have surgery this year. That's when I decided it's just not worth it,' he said, displaying a 10cm scar.

In September this year, he walked into the Christian Care Services' Singapore Care Centre halfway house in Geylang and went 'cold turkey'.

He recounted how he was at one time a property agent earning just under $5,000. He spent most of his income on drugs.

Initially, he bought Dormicum at $7 a pill from various clinics. He later bought the pills on the black market at $55 for 10 tablets.

The liquid mixture he injected into himself included about five or six sleeping pills and dissolved Subutex pills. 'It gave me a high but my actions were very exaggerated and people around me could tell that something was wrong.'

When he finally went cold turkey, the suffering was immense. 'I couldn't sleep or relax, my whole body ached and I felt cold all the time. I would just sit outside my room and wait for it to wear off.'

After seven days, he reached a tipping point and could overcome the withdrawal symptoms.

Since September, he has been living at the halfway house. Today, he will have been drug-free for three months and be allowed to leave the compound for a few hours. His first stop is to visit his 68-year-old widowed mother in Bishan.

But his recovery is far from complete.

Admitting it is an uphill battle, he said: 'I would be lying if I said I didn't still think about drugs. But this is the best I've felt in 20 years. I want to start on a clean slate.'