I often hear, "You should never cheap out on a good office chair, shoes, underpants, backpack etc.." but what are some items that you would feel OK to cheap out on?
This can by anything from items such as: expensive clothing brands to general groceries.
Brands pay a lot for branding, and thus charge more. The formulas are moderated and regulated by the FDA, so unless you enjoy paying for ads, get the generic.
This isn't always true. The content has to be the same, but the delivery mechanism can be different in generics as long as testing shows similar results
Unfortunately, generics can vary wildly in efficacy & quality. As @Aradina pointed out, sometimes the encapsulation is different (e.g. extended release coating vs. standard release), but also the form of the drug can differ (e.g. capsule, tablet, softgel, chewable, etc), chemical by-products from different manufacturing techniques may be present in different amounts, and different manufacturing processes can also yield different chiral enantiomer ratios in the end product.
The "same" drug from different manufacturers may vary in effectiveness / side-effects, and brand-name drugs aren't always the best formulations for most patients.
Generics are required to be as efficacious as name brand in the US.
I do not understand your point on encapsulation and the form of the drug. Name brands can have different encapsulations and forms within their own line. That has nothing to do with it being name brand vs. generic.
As someone who takes Adderall daily and has for many years, I can tell you the Teva brand generics work very well while the malinkrokdt (sp?) in the same dosage do almost nothing, and I crash very fast and need a nap in the afternoon and have to go to sleep early.
Conversely, I got some random Indian-HQ brand from Walmart many years ago (a pink tablet) that kept me up for 3 days. I was begging God for sleep. Placebo or nocebo my ass. Pretty sure someone "accidently" added a methyl group and was overly gracious with the dosage.
But it's also noticable in OTC meds. If you get real, severe inflammatory pain (not 'oh I have le headache'), buy a bottle of ibuprofen from the local dollar store and then buy brand-name Ibuprofen from a big box store, and blind test yourself.
(I may be misremembering the specifics on this part) Generics can only be 80% similar to the brand name in formulation, and often times they use fillers and binders that aren't as good as the formulation created by the R&D department of PharmaCo.
I'm not saying generics do nothing, I'm just saying my boss asks me what's wrong when I can't get my Tevas filled and have to use another manufacturer.
I've got a family member with a rare allergy. I've found that sometimes one or the other will have the allergen in it, but it's not consistent between generic/branded. Always check the ingredients and never assume it's exactly the same just because they have the same active ingredients
Drugstores here (Denmark) are required by law to ask if you'd like to buy the cheaper alternative to brand medicines. They will often change from week to week so a typical order at the drug store would be "I need this" - "I'll grab it for you but are you OK with cheapest alternative?"
Technically no. The tolerances should be more or less the same (generally 90%-110% label claim for the active ingredient) . Manufacturers aim for 100% and generally hit that target (or get very close to it).
The bioavailability could be different though - if you are doing a bioequivalence trial for generic VS brand, the generic would have to be between 80% - 120%. This difference is generally a result of the starches, fillers, and other stuff that may be in a generic formulation.
Same net effect as your comment (wider tolerances), but there is a bit more nuance.