It's great if you want a lot of fat and some protein in the morning. I actually mix in a bit of vanilla flavored protein powder as well for flavor and protein (adds a little sugar but whatever).
I don't think it's some magical energy drug, that's probably all placebo, get some adderall if you want an upper. But if you've trained your body to consume fat for energy rather than glycogen, bulletproof satiates that for a bit, so it's a nice breakfast replacement.
I personally found protein shakes or hard boiled eggs to be an easy way to start the day when I did eat breakfast. I have tried the coffee before at cafes and didn't like it, didn't think it was some kind of miracle upper too (compared to say coffee.)
I've had bulletproof coffee, and it's just O.K. More of a marketing gimmick than a super coffee-bean.
I do enjoy butter-coffee though, especially as a someone who follows a semi-keto diet.
If you like the taste go for it. Add a little bit of butter to your coffee and shake it up and what not. And I'd skip any extra oil/drop additions.
"Bulletproof Coffee", a coffee drink with butter and medium-chain triglyceride derived from coconut oil.
Medium chain triglycerides are medically recommended for people with very serious gut issues, such as stomach cancer or cystic fibrosis. The last time I tried to find a handy source for that factoid, I couldn't readily do so. Suffice it to say I have CF and this is common knowledge in the CF community.
MCT oil is readily absorbed without having to be broken down. In fact, it can be absorbed topically. So it literally requires zero digestion to be put to use by the body. In some circles, this is interpreted to mean that it is valuable because no calories are wasted on processing it. My personal opinion is that detail is probably largely irrelevant and it is probably more important for other reasons that the process of digestion gets skipped.
MCT oil is also beneficial to gut flora. Additionally, the gut contains about 70 percent of your immune cells.
So if you have any kind of (possibly unidentified) gut issue or immune problem, the MCT oil may be beneficial for that reason. People who have such issues and discover MCT oil typically have glowing things to say about it.
If you don't have any such issues, you may not think it is anything special.
You can look up studies on the health benefits of coffee. I do freelance writing and have written a few articles on the topic. Among other things, it boosts performance if consumed an hour before your workout.
I have not specifically tried this coffee, but my firsthand experience is that caffeine plus healthy fats can do miraculous things for me when I need it. I used to eat butter sandwiches with lots of diet coke when I had a lot of pain. The combination of two chemically significant foods can have a multiplier effect.
Having said that, I imagine that someone in generally good health will likely find it yawn worthy at best, if not downright revolting. My condition is better than it used to be. I cannot possibly choke down half to three quarters of a stick of butter anymore, which I used to do pretty often.
A good practice is start a food journal. Keep it for a bit to establish a baseline. Introduce one and only one change to your diet. Track it for a couple of weeks minimum. This is the best way to see if it does anything for you in specific.
/not medical advice, just me trying to occupy myself while recovering from a stupid fall
Coffee is fine. Butter is fine. Mixing them together is nothing special.
Adding butter does not help you lose weight. At least not directly. It could help you feel satisfied so you end up eating less than you may have otherwise.