What is the difference between amphetamines and methamphetamines?

Answer 1

Methamphetamine is "methylated," meaning that it is water soluble. This means it is more quickly absorbed by the human body and can be injected than non-methylated amphetamine. Otherwise, there is no difference. In fact, methamphetamine breaks down into amphetamine once it's ingested.

The outer membrane of the neuron cell is water soluble, this methylated property along with it's molecular size allows the chemical to pass through this barrier and influence the chemical messenger's or neurotransmitter's, (serotonin, dopamine, etc) receptors agonisticly. I think methamphetamine breaks down to amphetamine once it is metabolized or biotransformed.

This isn't correct. Methamphetamine is methylated, and there for it is now more fat soluble. Meaning that it crosses the blood brain barrier much easier, without having to circulate through the blood over and over again to be absorbed into the brain. When it comes to dissolving in water or ethanol. It has to do with the PH of a compound. Meaning which physical form it appears in, either a salt or freebase compound. Salts are typically water soluble making it possible to iv or snort. Freebases usually have lower vaporization points making them easier to smoke. Like crack compared to cocaine.

Answer 2

Chemically, methamphetamine possesses an N-methyl group which amphetamine lacks; otherwise, the compounds are identical. This structural modification results in methamphetamine being a more powerful stimulant and euphoriant. However, methamphetamine is also more toxic than amphetamine.

It should be noted that methamphetamine and amphetamine can exist as two distinct enantiomers (mirror image compounds). In amphetamine, both are active and have generally similar effects. However, the enantiomers of methamphetamine vastly differ in their pharmacological properties. The dextro (S) compound is a powerful centrally-acting stimulant, while levo (R) isomer has little CNS activity.