This ringbound book provides a reproduction of the important military reference, Dietary Supplements and Military Divers, A Synopsis for Undersea Medical Officers. It includes detailed information on over 70 supplements, with information on sources, chemical composition, mechanisms of action, reported uses, dosage, scientific evidence, adverse events, drug interactions, contraindications, comments, and references. There is coverage of energy enhancers, fat burners, testosterone enhancers, energy bars, sports gels, and more. Substances covered include caffeine, ginseng, polylactate, inosine, coenzyme Q10, bee pollen and royal jelly, ribose, DMAE, ephedra, ephedrine, chromium, chitosan, L-carnitine, HMB, pyruvate, synephrine, HCA, CLA, androstendione, DHEA, gamma oryzanol, ferulic acid, smilax, ZMA, ecdysterone, methoxyisoflavone, designer steroids, yohimbine, protein and amino acids products, whey protein, colostram protein, casein, melatonin, creatine, glucosamine/chrondroitin sulfate, gugulipid, SAMe, 5-HTP, choline, cobamamide, sports bars and gels, carbohydrate gels. The variety, availability, sales and use of dietary supplements (DS) remain poorly understood by the mainstream medical community, but the potential for use and abuse of DS cannot be taken lightly by undersea medical officers (UMO). Despite the indisputable pharmacologic effects many of these over-the-counter (OTC) products exert, the use of DS is generally overlooked by clinicians. DS information is not covered in much depth, if at all, in medical education, and physicians are not trained in this area. As such, many may feel uncomfortable with their lack of familiarity regarding the ever-increasing supplement pharmacopoeia. Peer-reviewed scientific research and evidenced-based information are often limited. Moreover, because the general public and active duty community perceive these natural substances as harmless, the products often do not come to the attention of physicians at all. Less than half of all users of DS consult a physician or a practitioner about alternative products. Whereas the literature on DS use is limited, research specific to use of DS under extreme environments is even sparser: virtually no studies have been conducted in hyperbaric / undersea environments. Due to the physiologic and psychological challenges of these extreme environments, military and civilian restrictions on the use of most medications in aviation and diving are quite specific and very strict. Because DS are not regulated by the Food and Drug Administration (FDA) as drugs, specifics regarding their use have not been addressed in diving regulations. To date, US Navy divers are not required to disclose their use of supplements, nor has it been common practice for UMOs or civilian equivalents to inquire about such use. However, considerable risks are expected with the use of many DS that are currently marketed. The safety and efficacy of most DS are not known for environments encountered routinely by the military diver. The purpose of this manual is to allow the UMOs to become familiar with common DS and make appropriate clinical decisions in light of the physical and psychological stressors of the hyperbaric environment. Concerns about DS use in the diving community include limited research on safety and efficacy, ease of availability, questionable sources of information, unfounded and exaggerated claims, and the unique mental and physical demands of military missions. In addition, there is no requirement for pre-market safety or efficacy testing (Aeromed). Because DS cannot be patented, there is little interest or funding for research on efficacy.