Background: Nutraceuticals are pharmacologically active substances extracted from vegetable or animal food and administered to produce health benefits. We recently reviewed the current evidence for nutraceuticals in patients diagnosed with heart failure as part of the writing of the Australian Guidelines for the prevention, diagnosis, and management of heart failure. Methods: A systematic search for studies that compared nutraceuticals to standard care in adult patients with heart failure was performed. Studies were included if >50 patients were enrolled, with ≥6 months follow-up. If no studies met criteria then studies <50 patients and <6 months follow-up were included. The primary outcomes included mortality/survival, hospitalization, quality of life, and/or exercise tolerance. Iron was not included in this review as its role in heart failure is already well established. Results: Forty studies met the inclusion criteria. The strongest evidence came from studies of polyunsaturated fatty acids, which modestly decreased mortality and cardiovascular hospitalizations in patients with mostly New York Heart Association class II and III heart failure across a range of left ventricular ejection fraction. Coenzyme Q10 may decrease mortality and hospitalization, but definite conclusions cannot be drawn. Studies that examined nitrate-rich beetroot juice, micronutrient supplementation, hawthorn extract, magnesium, thiamine, vitamin E, vitamin D, L-arginine, L-carnosine, and L-carnitine were too small or underpowered to properly appraise clinical outcomes. Conclusion: Only one nutraceutical, omega-3 polyunsaturated fatty acid, received a positive recommendation in the Australian heart failure guidelines. Although occasionally showing some promise, all other nutraceuticals are inadequately studied to allow any conclusion on efficacy. Clinicians should favor other treatments that have been clearly shown to decrease mortality.