For cannabis, there are three main types of extraction methods: butane, CO2, and ethanol. Recently, people have been finding ethanol extraction to be in some ways superior (leafly.com). Ethanol extracts the full spectrum of cannabinoids and terpenes. This is great, because many people want the effectiveness of full spectrum products. However, this method also extracts chlorophyll which can cause some unwanted side effects. The chlorophyll can be removed by filtering the liquid, but this lessens the potency of the end product (marijuanabreak.com). With CO2 extraction, there is a much more potent product without chlorophyll, but more work must be done to make the end product full spectrum (marijuanabreak.com).
Ethanol also destroys the waxes in the cannabis plant which have medicinal properties themselves (projectcbd.org). Using solvents such as alcohol for distillation leaves the risk of potential unwanted contaminants (meetharmony.com). This method is rarely recommended by healthcare professionals or scientists due to its unpredictability and risk of contamination. It is also possible that residue may be present in the oil that would take away from the benefits of the product. This method is not often used for vape products and mainly used for tinctures (cbdhempoilusa.com).