Latte, cappuccino, flat white...bulletproof. Yep that's right there's a new souped up coffee on the barista's block and it's taken the Insta world by storm.
In case you haven't heard of it already, Bulletproof coffee is coffee with added butter and medium chain triglyceride oils (MCTs) or coconut oil.
If you listen to the online chat, fans of the bulletproof version of the brown stuff claim it gives you a long-lasting energy hit, nails your focus and keeps you feeling full.
Followers of the trend say the caffeine combines with the fats and slowly releases its effects into the body over a long period of time.
"Bulletproof coffee, whilst a popular trend for its supposed weight-loss benefits, may not be for everyone," explains Wyatt Cavalier, is co-founder of Bibium and Underdog Coffee.
"It's a calorie dense and satiating beverage, designed to fuel the body for hours and it's a particularly popular trend at the beginning of the year, as many people start hitting the gym again and look for highly calorific meal replacements to seemingly boost their workouts.
"It's thought that the blend of caffeine and high-powered fats can increase your energy levels, more than the average Espresso or Americano," he adds.
So how does the science stack up?
"Proponents of bullet proof coffee claim combination of the fats with the caffeine can slow down the absorption of the caffeine which can mean steadier energy release," explains nutritionist Rick Hay.
"Caffeine itself increases energy and boost circulation so there are benefits and benefits to cognition too."
The hot drink is also flouted as a weight loss tool as it is high in medium chain fatty acids which stimulate fat burning when combined with intermittent fasting.
But some experts are warning that giving your coffee a calorific hit might not be entirely good for you.
"The health risks increase if you are already overweight or obese and your aren't moving enough – taking on excess calories in this instance is not good for cardio vascular health," explains Rick Hay.
"Also if people consume too much bulletproof, as is the risk with any trend, they could become more jittery and anxious," he adds.
"It's understandable that health experts may not be on board with the bulletproof trend as the drink is high in saturated fats, reduces your nutrient intake and with evidence and studies lacking, it probably shouldn't be relied on for weight-loss or as a meal replacement for any 'new year' diets," explains Wyatt.
"Overall though, coffee in moderation can improve your concentration, boost your mood and make you more productive throughout the day."
There are other ways to get a natural energy hit if bulletproof coffee's not for you.
"If you're looking for an alternative option, you may want to try a black, unsweetened coffee for a healthy workout boost," suggests Wyatt. "If you are not a black coffee fan, almond milk is great healthy alternative to cow's milk and takes the bitter edge off of black coffee."
Rick Hay recommends adding some cinnamon to your coffee which helps to regulate blood sugar levels which in turn could mean more steady energy.
"You could also try something like honey or coconut sugar to give a natural boost. Or add a little cacao to give you a lift," he adds.
And if you do fancy trying out the bulletproof trend, Rick Hay suggests you stick to one a day, preferably early on.