You can do whatever you want....results may vary though ๐
I am not a doctor, but have been told by GPs and Pharmacists in the past to increase dosages over the recommended on the packet. I'm not a small person, and the doses on packets are very conservative. Not something one should do regularly, but on as needed basis.
The recommend dosages have massive safety tolerances built in, you can eat a whole box of them will just hallucinate with no lasting problems.
The one regular medication to never to do this with though is paracetamol (Panadol / Tylenol). Never take more than 8 a day. Your liver only has enough of a particular enzyme to process that much in 24 hours without causing damage. It's surprising that it's legal to buy tbh, that stuff is dangerous.