The core of the Breuss Cancer Cure is a rigid diet, which consists of a 42-day fast in combination with special vegetable juices and teas. Additional recommendations are included, for instance, to avoid so-called water veins. According to Breuss’ theory, cancer requires solid food to survive in the body.

Amygdalin is a naturally occurring plant compound belonging to the group of cyanogenic glycosides characterized by the release of cyanide upon enzymatic degradation. It is primarily found in the seeds of apricots, peaches and bitter almonds and also in plants such as lima beans, clover and sorghum. Laetrile is an acronym (derived from LAEvorotatory and mandeloniTRILE) used to describe a purified, semi-synthetic form of amygdalin. Laetrile is claimed to be an anti-cancer treatment or even cure, and cyanide is thought to be the active anti-cancer ingredient. It was at the height of its popularity in the U.S. in the 1970s and 1980s until the FDA considered it unsafe after a phase I and phase II controlled clinical trial in 1982 found no evidence for the efficacy of laetrile and highlighted considerable safety concerns including cyanide poisoning.

PC-SPES, PC-HOPE, PC-CARE and PC-PLUS are herbal supplements which have been marketed for the promoted for prostate health and treatment of prostate cancer. PC-SPES, the original product consisting of a combination of eight herbs, is no longer available. It was recalled by the US Food and Drug Administration (FDA) in 2002 due to concerns over quality control and reported contamination with prescription drugs. Newer products including similar herbs produced under improved conditions to avoid contamination include PC-HOPE, PC-CARE and PC-PLUS.

Carctol® is an Ayurvedic herbal mixture consisting of eight herbal extracts, which was developed by Dr Nandlal Tiwari in India.

The Ornish diet and lifestyle modification programme combines a supplemented vegan diet with exercise, stress management, and group support sessions. The programme is claimed to enable patients with early-stage prostate cancer to delay or avoid conventional treatment and/or improve quality of life. However, only one randomized trial and one pilot study have been published, all using surrogate markers for prostate cancer. In prostate cancer patients, the programme was found to improve cardiovascular health parameters, which is important as cardiovascular disease is the primary or secondary cause of death in men with prostate cancer.

Ozone (O₃) is an unstable gas found in the atmosphere. It consists of three oxygen atoms and is therefore a strong oxidising agent. Medical ozone is generated via high-voltage oxygen conversion. Application methods range from local treatments to rectal insufflation, ozonated water, and autohaemotherapy. Therapeutically it is mainly used for its antimicrobial and anti-inflammatory properties. Claims include treatment of diverse conditions such as cancer, infections, diabetes, and neurological or inflammatory diseases

Aromatherapy entails the controlled use of essential oils that have been extracted from a variety of plant sources. Therapy is usually given via massage, inhalation or a foot- or full-body bath. In cancer care, aromatherapy is primarily used as a supportive treatment to manage symptoms and adverse effects associated with cancer and its treatment, especially for anxiety, nausea, sleep and some pain. It acts mainly through olfactory/limbic modulation and specific molecular targets.

Carnitine is the generic term for several compounds including L-carnitine, acetyl-L-carnitine, and propionyl-L-carnitine. It is a substance occurring naturally in humans, where it is synthesized endogenously in the liver, kidneys, and brain. Carnitine is naturally present in many foods and most of the daily requirements of L-carnitine is provided through the diet. It is also available as a dietary supplement. In the context of cancer, L-carnitine has been mainly investigated for alleviating adverse effects of chemo- or radiotherapy treatment.

In Insulin Potentiation Therapy (IPT) insulin is used alongside conventional chemotherapy. It is claimed that insulin enhances the effects of chemotherapy, enabling a 75–90% reduction in the usual doses of anticancer drugs and thus reducing the risk of adverse effects. Although some hypotheses have been put forward, the mechanisms of the claimed insulin potentiation of chemotherapy remain unclear and the few published in vitro studies do not help to clarify this.

Milk thistle herbal products are made from seeds of Silybum marianum. Milk thistle has a long history of medicinal use, particularly in the treatment of digestive and liver disorders. Claims in relation to cancer are that milk thistle prevents cancer initiation and development, reduces adverse effects of chemotherapy and radiotherapy, and supports the action of some anticancer drugs.