Need some advice

So at the end of this week I am going to buy some Choline Bitartrate supplement tablets for LDing.
I have fairly strict parents, especially when it comes to stuff like this. (Step mother is a pharmacist)
I have no idea how I am going to explain to them why I am taking supplement tablets such as these, like what the hell do i say to them?

I have tried explaining LDing to them before, but they just give me a blank look and change the subject.

Any ideas on how to tell them?
or should i hide them?

p.s
Is there a particular age you have to be to buy supplement tablets from Holland and Barretts? (UK users)

you could just eat hard boiled eggs before bed and avoid the hassle. one egg has something like 112mg of choline.

and yeah! it would be awkward trying to explain it :?

well i told everyone as soon as i found out about it. i just said "guess what, i found out how to control my dreams, its awsome, you should try it". then i got a bit of opinions on it, some good some bad.

i think you need to be 16 to buy chemicals. im not entirely sure, i went into a shop to get chemicals and i was told i needed to be 16(this was when i was 15) but maybe it depends on what it is you're buying.

I see no reason to tell them if you think they would oppose. As long as you know that it will not hurt you in any way, I say you should be free to take whatever you want.