The thick oil is not highly marketable as an illicit drug because it cannot be easily injected or snorted, and is often associated with vein damage among people who inject it. Therefore, manufacturers attempt to purify methamphetamine base (oil) into methamphetamine hydrochloride (crystal). To successfully complete the process requires considerable chemistry expertise, so the resulting product is often a pasty, sticky powder that has a yellow or brown hue due to the presence of iodine and other organic impurities, and generally requires heating to sufficiently dissolve it for injection. Organic impurities are an indication that the purification process was not performed accurately, preventing the substance from forming into the large translucent crystals typical of 'ice'. Base is not common in Southeast Asia, but is known to be manufactured in Australia. It is usually of fairly high purity.
'Ecstasy,' or methylenedioxymethamphetamine (MDMA), is a chemical derivative of methamphetamine. Although both are stimulating the CNS, they produce different chemical interactions in the brain: ecstasy primarily affects serotonin, which mediates emotional systems, while methamphetamine causes the release of high levels of the neurotransmitter dopamine into areas of the brain that regulate feelings of pleasure. However, since ecstasy can garner higher prices, methamphetamine tablets are often sold as 'fake ecstasy', with the same weight, color, and logo, and often include ketamine in an effort to mimic the effects of MDMA. MDMA is less common than methamphetamine in Southeast Asia, but it is still used in most countries of the region.