Celebrities like Shailene Woodley, Harry Styles and Bhumi Pednekar may have become adept at touting the benefits of coffee as medicine, but its use could actually cause more harm than good–especially if certain health concerns exist.

Bulletproof coffee is a blend of coffee, unsalted grass-fed butter and MCT oil that’s often popular among those on ketogenic or low-carb diets as it can give an energy boost, reduce hunger and aid fat loss. Furthermore, some individuals also use it as a meal replacement, especially breakfast time.

Bulletproof coffee’s MCT oil, typically made of coconuts or palm kernel oils, is designed to increase metabolism by turning fat into energy quickly. Its shorter chain of triglycerides makes for rapid absorption by your digestive system and bloodstream for immediate energy without having to store it as reserves. In addition, some people add other nutrient-rich ingredients like collagen protein powder (for skin and gut health) turmeric powder (to relieve inflammation) or adaptogens like lion’s mane reishi and ashwagandha that help relieve stress.

Although these ingredients may sound appealing, there is very little scientific support for their claims. For instance, the high amount of saturated fat present in Bulletproof coffee may raise cholesterol and increase heart disease risks. Furthermore, caffeine in coffee may affect sleep quality which in turn impacts overall health and performance.

At its core, Bulletproof coffee should not be taken by those with high cholesterol levels, heart disease or diabetes without first consulting their physician and taking additional measures such as using alternative sweeteners like xylitol or stevia to limit sugar intake.

If you decide to give this drink a try, be sure to use high-quality coffee beans that have been properly roasted and ground. Seek out organic and Rainforest Alliance Certified farms as these will guarantee that the beans have been grown without herbicides or pesticides and adhere to high standards in order to safeguard both workers’ rights and environmental sustainability.

One cup of Bulletproof coffee containing two tablespoons of MCT oil and grass-fed butter will contain 22 grams of saturated fat–well above the 13 gram per day recommended by the American Heart Association for someone on a 2,000-calorie diet. Furthermore, only use MCT oils from brands which guarantee it to be free from trans fats.

Though evidence for these claims remains scarce, some individuals do report finding Bulletproof coffee beneficial in providing energy and less hunger than before. But for most of us, maintaining optimal health requires sticking with a balanced diet and exercise regime.