There are natural ways to boost your immune system. Get more antioxidants like vitamins A, C, and D while cutting sugar, salt, and fat. Strive for 150 minutes of exercise a week, 7-8 hours of sleep a night, and 64+ ounces of water a day. Avoid nicotine and alcohol and work on stress relief.
There’s a lot of scientific evidence proving essential oils do work. For example, lemon can help with mood, lavender can aid with stress and anxiety, and peppermint can improve your breathing when you’re sick. Yet, a lot of the effects might be a result of the placebo effect.