for detailed info do a search on each product and you will learn a lot more. anyway esciline is irritating to the muscle and inflames it causing it to look bigger, it is water based and can be injected with an insulin syringe. synthol is an oil which basicaly takes up space in the muscle belly causing it to grow in size. sort of like a water balloon. In my experience it really gives you a smooth look depending on which muscle you are injecting into. the results last longer with synthol. escil. is usually used precontest, if it can even be found.