What is Captagon, the highly-addictive drug some say funded the Assad regime?

Just days after the fall of Syrian leader Bashar al-Assad, rebel fighters who have taken hold of Syria's capital Damascus, have uncovered huge stockpiles of Captagon, an illegal amphetamine that's long been mass-produced in the country.
Video have been shared on social media of Syrian factories containing secret stashes of the drug.
What do we know about the substance that is believed to have kept Assad in power for so long?
Captagon is an illicit drug that is cheap to make and of which vast quantities can be produced in a relatively short period of time. It acts a bit like a stimulant, making the messages between your body and your brain move faster.
Bashar al-Assad was accused of turning Syria into the world's leading manufacturer of Captagon, with his family believed to have made billions shipping the drug all over the world.
It is believed to be popular in parts of the Middle East, but shipments have been smuggled into Europe and to the UK.
There have been several high-profile attempts to crackdown on the manufacturing of Captagon. Videos posted online also show piles of the drug being burned by groups once the packages reach their destination.
It appears to have had little effect on the production.
The amphetamine is often hidden inside vegetable crates and electrical goods for export. Some experts, including those at the Observatory of Political and Economic Networks, suggest almost £10 billion year was generated for Syria through its sale. Two billion is thought to have gone directly to Assad and his family.
Experts who study the drug say they fear that people are not aware of the risks the drug carries, as it is not as well known as drugs like cocaine and ecstasy. It is also thought to be popular in many Muslim countries where the drug is often seen as an alternative to alcohol.
This latest stash found by opposition group Hayat Tahrir al Sham, also known as HTS, has been burned and destroyed.
A new government still needs to be formed in Syria after Assad was ousted.
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