Alchemy is like shamanic plant medicine only the mineral kingdom and instead of threshold psychedelic experiences it's a much more slow and gentle perceptual dissolving of emotional baggage.
Generally speaking you work with one or a few at a time and start at the beginning as they are not more potent necessarily in strength but get more deep and subtle the further down the line of alchemy you go.
So you would start like everyone does with Alkhem, Helios Platinum and Gold, or Lumin and then after working with it for a month or so ( give or take) you just pay attention for the gradual "call" of the next one. It's subtle and difficult to explain it just happens. But if you don't feel a call in general you just after 3-6 weeks ( again general terms) move on to the next one. You don't have to finish the bottle and often times you can swing back around to it later( the unfinished alchemy and use it if it feels appropriate months down the line. I love Alkhem as it always can bring me a sense of "house cleaning" internally.
The next trajectory might be Innerphaz,Phasix or 7 rays and you might even look at the other individual phases that make up the Helios line of alchemies. If you need assistance you can ask me and I can help you pick out the next thing. Alchemy is like a food for your inner world/mind. If vitamins are for your physical body. Does that make sense?
As far as dosage we have suggested doses that come with the alchemy but the bigger instruction is to start to develop a working internal guidance relationship with the alchemy. You may not need to dose everyday. Sometimes it might be just once a day maybe some days you dose once in the morning and once the evening. It changes and that is because what you may need is dynamic. the way I do it is I hover my hand over the bottle and if I get an "internal green light" then I use it. Some people use a pendulum to ask which alchemy is the right one and how many drops. Take with food or not does not matter. Some people it keeps them awake and they can't take it at night. I enjoy taking the alchemy at night myself as I think it helps me process things while I sleep. Hope this helps to clarify.