Do I have to take supplements?

I will only ever recommend 3 supplements to those on a fat loss or muscle building journey, and those are protein, creatine, and caffeine. These 3 are the only supplements with adequate enough scientific research to warrant purchasing and using.

Protein supplements are a powdered form of protein that comes from plants like soybeans, peas, or hemp, or from milk like casein or whey. In a systematic review (Pasiakos et al. 2014), protein supplements had no statistically significant impact on lean mass and muscle strengths during the initial weeks of training, but as the frequency and volume of resistance training increased, the protein supplementation promoted muscle hypertrophy and enhanced gains in muscle strength. There is also evidence that protein supplements can increase aerobic and anaerobic gains. The recommended amount of protein your body needs is around 0.36 grams per lb of body weight for basic bodily functions, not muscle growth, so if you're not meeting those numbers through your diet, incorporating protein supplements can aid in that.

Creatine is a natural compound that serves as a source of energy for your muscles. It provides a steady supply of energy to your body so that it can efficiently work, especially while exercising. Naturally, it comes from red meat, seafood, and animal milk, but your body also produces it in your liver, kidneys, and pancreas. A scoping review (Wu et al. 2022) studied the use of creatine supplements in various populations and found that it is an efficient form of supplementation for muscle growth within younger populations with adequate training. Studies with older populations still need more studies to definitively determine the effects. Studies show that creatine can cause a 2-3 lb increase in lean muscle mass when 3 grams a day are supplemented.

Caffeine is a drug that stimulates your brain and nervous system and can increase the circulation of cortisol and adrenaline. It is found naturally in the fruit and leaves of some plants, but most people know it as the core ingredient in coffees, teas, pops, and energy drinks. By itself, caffeine does not increase muscle growth, but a study looking at the effect of caffeine on exercise performance (Guest et al. 2021) found that caffeine supplementation increases muscular endurance and performance when 3-6mg/kg of body mass doses are taken. Therefore, despite not causing muscle growth, caffeine has effects on your behavior that can lead to muscle growth, such as more motivation to go to the gym and better endurance to push during training.