Double Scoops (they aren't kidding!) Bra Insert Review
I tried another bra insert which I had read a good recommendation of. These are Double Scoops, and they come in a pair for $19.99. They are available for purchase on Amazon at https://amzn.to/3y7Smt5.
You should purchase these in the cup size of the bra that you want to wear them in, rather than the size that you are looking to achieve. All sizes have a similar thickness, but they vary in the total amount of coverage, and this is to make sure they will fit well inside the corresponding cup size of your bra. Too small and they might not stay in place inside the bra; too big, and your bra cups will be too small to contain them horizontally and/or vertically.
Double Scoops are similar to the Femagique inserts: foam, and graduated with most of the volume at the bottom. However, these add significantly more size, probably at least one cup and on me it looks more like 1.5. I'm impressed, as usually inserts that promise to add a cup size don't really deliver and their purpose is more to help you fill out bras you already have that are a little too big or have gaps at the top.
Another thing I like about them is that the tops of the Double Scoops close entirely over my breasts, so there isn't a problem with what I call "whoops sudden nipple reveal," or with the inserts sliding up to an awkward place inside the bra. They stay put just fine in my lightly lined 34C bra, which I had been looking for something to help me fill out. In fact I think I could even go up a cup to a D with them in, but my 34C has enough stretch in it that they work fine. Keep in mind I am really not a C cup and I only own this bra for using with inserts in the first place, so I'm not sure you could use these with your usual bra size unless all of your bras are already way too big in the cup for you. It's worth trying them with a bra in a cup size larger than you normally wear.
The 34C bra I put them in (shown at left) is a plunge style with flexible fabric cups that have an overlaid layer of mesh lace. I recommend this type for inserts, rather than trying them with a rigid contour-cup bra or with anything else that already has foam inside. The foam will not adjust to the inserts as well and you may end up with gaps, or with the insert moving around a lot inside the bra cups. With these inserts in this particular bra, I don't have either of these issues. It's all about getting the right match between your inserts and the bra you wear them in, which I realize sounds very complicated, and it really sort of is. I've had to try many combinations to find something that works this well.
If you are looking for a full-cup enhancement solution and do not have much natural breast tissue, it's possible you could get away with these; however, they are not full breast forms and it's best if you have at least a little to help fill the tops of them. Many trans women may have enough volume to pull this off, but I am not sure that they would work if you are a breast cancer survivor and have had a non-augmented double mastectomy. So to be on the safe side, I am recommending them only for assigned females at birth who are looking to add more size to what they already have, and to trans women who have some amount of natural breast tissue that they can work with. If you have had a double mastectomy and want to try these, make sure you use them inside a non-padded bra that is relatively full-coverage so that it closes completely over the top of your chest. I would not advise trying to wear them inside a balconette or push-up style.