I had a conversation with my pharmacist about this recently and you are essentially correct.

The active drug is identical, but the material used to make may be different and the coating may be different also. So a branded off the shelf tablet may, due to how it's made and the extra markup (Xofen Xtreme Pain relief) get to work 5-10 minutes before the generic version, or it may taste sweeter and be easier to swallow for children, be in gel form etc.

It's worth noting that this is different from the types in the article - https://www.accc.gov.au/media-release/court-finds-nurofen-ma... where products like Nurofen Period pain and Nurofen Migrane were the exact same thing.

Also the placebo effect is powerful, so maybe we shouldn't dismiss it as just marketing.

Quite. I can even feel the branding working on me even though I know it is rubbish. The nice shiny foil pack versus the plain basic package. The thought that perhaps the big company will have better quality control. I suppose complicating the matter is the placebo effect, especially as it is the area of pain relief which is the poster child for the efficacy of placebo.

The big company might well have better quality control (though, depending on the regulatory environment, you may have very good grounds to believe that everyone's quality control is good enough) -- but it seems unlikely that the same big company has better quality control for one product than for another identical product in different packaging.

But not impossible. You could imagine that they do some kind of tests on their pills, and put the "better" batches in the fancier packaging with the higher prices. I doubt it, though. (Though I bet such things do happen in other less tightly regulated markets.)

One area where it happens is electrical components; for instance, if you buy a bunch of 10kΩ ±5% reistors and measure their actual resistance, you should find a nice distribution with a big hole around exactly 10kΩ; those resistors were taken from the batch and sold as ±1% (or better) tolerance. But it shouldn't happen with drugs, I doubt there are "grades" of acceptable quality.

You're right about the placebo effect, I'm sure I once read about a study that found patients reported better pain relief from the pills with fancy packaging. As you said, we're dealing with pain relief which is inherently subjective, so the placebo effect matters.

My girlfriend is a doctor, and often goes for the branded versions, saying they will be better quality, and absorbed better.

I have read before that good quality vitamin pills are bigger so that they crumble / break down and get absorbed better that hard compact ones.

People fall for it because they don't know better. Nurofen treats headaches/migraines/whatever, ibuprofen... what the hell is ibuprofen, the doctor did not prescribe that!

I've seen so many people take overpriced multivitamins and specific brands for cold/fever when they could've taken generic paracetamol or bodybuilder supplement vitamins (much cheaper and higher dosages) that I don't even care anymore.

Either educate yourself and do some research or pay for the safe, overpriced brand.

Nurofen's manufacturer also sponsors medical conferences which use a large yellow sun with giant gradiated halos (ie, the Nurofen branding) throughout the conference materials without mentioning the name 'Nurofen' as they are legally forbidden from doing so.

Fillers and method of delivery can and do often differ between generics and name brand drugs. Though in practice very few people are really affected by that.

I'd say this is true is most cases. In the US, generic drugs only need to be 80% to 125% bio-equivalent (AUC, peak concentration, etc). For most drugs that's fine.

However, there have been a few that have gotten recalled because they weren't bioequivalent. Wellbutrin is a great example. It took the FDA a couple years to finally force the manufacturer to redo the tests and fix the problem.