I've tried Piracetam, Aniracetam, and Coluracetam & Phenylpiracetam. It's worth keeping in mind that the reviews and responses people give online tend to range from "WOW THIS HAS CHANGED MY LIFE" (which inevitably is followed up by a post a few weeks later indicating x-racetam has lost all effectiveness) to people claiming they feel no subjective effects whatsoever, whether they be positive or negative. However, for many people the end result is often somewhere in the middle. Nothing groundbreaking, but substantial enough effects to continue a responsible dosing schedule.
There is no single nootropic on the market that will give you the effects of the drug Bradley of Cooper takes in Limitless - otherwise everyone would already be taking it! It's important to keep your expectations realistic, specially when you hear people claiming all these wonderful benefits have come about. Just like with any drug/supplement/med available to me & you out there, your mileage may vary. What works for one person will do FA for another, and and vice versa. I've written my individual experience of various racetams below, but what you experience is unlikely to be the same. Here goes!
Piracetam: Probably the most-used and well-known racetam out there. When it worked it would eliminate any existing brain fog in my head and increase a sense of focus throughout the day. Some days I barely noticed anything though. If you struggle with a poor working memory including every day stuff like "arghh what's the word..." "what's that bloke's name again?" or "way day of the week is it" I'd definitely give it a shot. This is also the cheapest racetam you'll find on sites selling nootropics 99% of the time - combine that with an excellent safety profile and its definitely worth a shot. If you're a coffee drinker I'd urge you not to expect the same kinda feeling from Piracetam, it's like to provide an improvement in alertness and overall mental function as opposed to any jittery physical energy from a strong cup of mud.
Coluracetam: There's a couple of studies showing Coluracetam's effectiveness in treating Major Depressive Disorder (MDD). It does seem to provide a real mood lift from anhedonia or even if you're feeling like you just need to get out of a funk. Compared to other racetams it's a heck of a lot more expensive though. Didn't notice any cognitive benefits, merely a decent mood boost. Unsure if I'd spend money on this again.
Aniracetam: Easily my favourite! Provides a real anxiolytic relief at 750-1500mg. From reading reports online this also seems to be the most consistent racetam...or perhaps that's just conformation bias lol. I love this so I'm gonna sing its praises, but keep in mind you mind be a non-responder. It's certainly nowhere near as anxiolytic as a benzo but whenever I've taken it there's never been any need/craving for a benzo because I've been able to function in any situation without it. I can be somewhat agoraphobic at times and this really helps me go about my day and get stuff done with little/no fear whatsoever. There's also an increase in the enjoyment of social interactions which is great if you suffer from any degree of social anxiety. Has a slight effect on cognitive function and mood but nothing to the extent of Piracetam or Phenylpiracetam (Oxiracetam is also meant to be great for creativity and focus).
Phenylpiracetam: Sort of like a mild Mod@finil. Excellent for relieving symptoms of ADHD...i don't know if it would even be possible to have a lazy day on this! This is known to be the strongest of all racetams, the only downside is that it can induce a sort of anxiogenic nature as opposed to an anxiolytic one. Kinda expensive too. Never tried it before but I think if you combined Aniracetam with Phenylpiracetam it might combat that anxiety though. Easily the best for zooming through ticking off your to-do list with an increased sense of focus and motivation.
If I could recommend one nootropic that isn't technically a racetam it would be Noopept. Nothing else has shown greater benefits to working and long-term memory. It's not euphoric or anything but it's great at stabilising your mood to say a decent 6 or 7/10. Which ain't too shabby
These aren't miracle pills...yeah they'll give you an edge or a boost but they won't change your life. For example, with Aniracetam you won't get a sudden WOW moment or feel super recreational... but as you're going about your day you'll notice a subtle change has occurred in your anxiety level and potentially your intellectual abilities. I wish I'd read this back when I first started spending money on nootropics because unfortunately there's sites that state these supplements will cure all your mental health issues and turn you into a genius when the reality is that's not going to happen. Keep your expectations grounded and you'll be satisfied.