In theory, there should be no difference between taking 4x200mg
ibuprofen tablets or 1x800 mg tablet.
BUT...
the FDA decides if a drug is available on prescription, or OTC (over the counter).
Prescription drugs are considered safe for use under the
supervision of a doctor, while OTC drugs are safe to use for self-medication providing you
read the label carefully.
In the case of ibuprofen, the OTC 200 mg tablet and the prescription 800 mg tablet are used to treat different conditions. The 200 mg OTC product is used for minor aches and pains, and the 800 mg tablet is used to treat conditions such as arthritis under the care of a doctor. Ibupfrofen can cause side effects (often serious) so it is really important to take only as directed. You will note the label of the OTC package clearly states a maximum dose, and maximum daily dose and by exceeding the recommended dose, without adequate medical supervision, you are putting yourself at greater risk of side effects.