Yes, absolutely.  It, of course, depends on the reason for your fatigue.  Fatigue can be caused by a multitude of things, from nutrient depletion to thyroid deficiency or adrenal insufficiency.  A great start would be a complete, professional grade multi-vitamin.

Often times, high quality fish oils with the symptoms of ADD/ADHD by improving mental skills, such as the ability to organize thoughts and improve attention.  L-theanine is also a uselful tool.  L-theanine is an amino acid that promotes relaxation and focus.

Insomnia is often relieved by highly absorbable magnesium, melatonin, GABA, l-theanine, and/or balancing of hormones.

Yes, natural alternatives to lower cholesterol include plant sterols, proper cellular nutrition, and niacin.

5-HTP, methylated B vitamins, GABA, l-theanine, and/or magnesium are often used to help with mood and anxiety.

Hormone production begins to decline during the late 20s.  Hormone imbalance can occur at any age, most commonly estrogen dominance.  I suggest having baseline hormone levels checked during late 20s and at least yearly thereafter, earlier if symptoms begin. Estradiol, progesterone, testosterone, DHEA, and cortisol should be included in the testing.