I'm having trouble making sense of this sentence. From what I've looked up, I think it's probably either "meme" talk, a dialect joke, or some combination of the two. Here's the full sentence:
This is from a manga. Two highschool girls are talking, and one of them bought a love potion from the internet. Her friend is doubtful of its effectiveness, but she says "no, no, it seriously works", mentioning that she'd even tested it on girls. She describes its effectiveness as バカ効き a few times throughout the manga so far because it ends up having unexpectedly erotic results.
If I'm breaking the sentence apart correctly, she's describing マジで; in other words, she's talking about how マジ the effectiveness of the love potion is. If that's correct, the description is バカがガードがばがばになっから.
がばがば could mean "oversized", "gag", or "baggy (like clothing)" according to Google. I assume ガード is just "guard", like the kind a person might let down if under the effects of a love potion, though that doesn't seem to make sense here. For なっから I found a meaning on fukapedia that says it's 深谷地方の方言 and is equivalent to とても or たいへん... but that again doesn't seem to fit properly.
I'd really appreciate any help with the word definitions themselves, or a hint as to how I might be breaking it down improperly. Thanks in advance.