Related Terms

  • ADHD, amphetamines, analeptic stimulants, attention deficit hyperactivity disorder, caffeine, central nervous system, CNS, methylphenidate, methylxanthines, nicotine, stimulant, stimulant abuse, stimulants.


  • Central nervous system (CNS) stimulants, also called psychomotor stimulants or uppers, are a class of drugs that speed up physical and mental processes. They temporarily make patients feel more alert and improve mood.
  • Stimulants are typically used to treat medical conditions such as attention-deficit hyperactivity disorder (ADHD), attention-deficit disorder (ADD), fatigue, and narcolepsy. Some stimulants have been used as appetite suppressants, although the safety of this use remains controversial.
  • Examples of CNS stimulants include amphetamines, such as methylphenidate (Ritalin®), methamphetamine (e.g. Desoxyn® or Desoxyn Gradumet®), caffeine (e.g. coffee or tea), nicotine (cigarettes or cigars), and the illegal drug cocaine.
  • Side effects of stimulants vary depending on the specific dose and type of drug. In general, side effects of short-term use may include anxiety, insomnia, dry mouth, depersonalization, feeling of euphoria, increased heartbeat, crying, dysphoria, decreased appetite, hyperventilation, irritability, depression, nervousness, paranoia, mood swings, restlessness, and shaking or trembling.
  • Most CNS stimulants are highly addictive. However, some newer drugs, such as modafinil (Provigil®) are less addictive.
  • Because stimulants are highly addictive and have euphoric effects on the brain, they are often abused and taken as recreational drugs. Long-term abuse of stimulants can cause changes in the brain and lead to serious health problems, including severe mental illness and memory loss.

Integrative Therapies


Unclear or conflicting scientific evidence

  • Acupressure, shiatsu
    : Acupressure is used around world for relaxation, wellness promotion, and the treatment of many health problems. Acupressure may improve alertness. Acupressure at stimulation and relaxation points may have different effects on alertness in a classroom setting. Further research is necessary to confirm these findings.

  • With proper training, acupressure appears to be safe if self-administered or administered by an experienced therapist. No serious long-term complications have been reported, according to scientific data. Hand nerve injury and herpes zoster (“shingles”) cases have been reported after shiatsu massage. Forceful acupressure may cause bruising.
  • Acustimulation
    Acustimulation is different than acupuncture. However, it uses Chinese acupuncture theory to locate points on the body where electrical stimulation is applied to reduce certain symptoms. Limited research suggests that acustimulation may help treat symptoms of fatigue. One study found that 15 minutes of transcutaneous electrical acupoint stimulation (TEAS) three times weekly for one month reduced fatigue and depressed mood, and increased sleep quality in patients receiving hemodialysis. However, the design of the study makes interpretation of the findings difficult. More studies are needed to determine whether acustimulation should be recommended for this use.

  • The only known side effect of acustimulation devices is slight skin irritation under the electrodes when the wristband is used. Switch wrists to avoid this reaction. Acustimulation devices should only be used on the designated area. Use cautiously with pacemakers. Avoid if the cause of medical symptoms is unknown. Keep acustimulation devices out of the reach of children.
  • Betel nut
    : Betel nuts come from the areca tree, a tropical palm tree. Betel nut use refers to a combination of three ingredients: the nut of the betel palm (Areca catechu), part of the Piper betel vine, and lime. Preliminary evidence suggests that betel nut may act as a stimulant. It is believed that small doses can lead to stimulant and euphoric effects, and betel nut chewing is popular due to these effects. Although all three ingredients may contribute to stimulant properties, most experts believe that chemicals in the betel nuts (alkaloids) may be responsible. Other substances that may be combined with betel nut chew, such as tobacco, may also contribute to its purported effects. However, chronic use of betel nuts may increase the risk of some cancers, and immediate effects can include worsening of asthma, high or low blood pressure, and abnormal heart rate.

  • Based on the known toxicities of betel nut use, the risks may outweigh any potential benefits. The use of tobacco as part of the chewed material may be a contributing factor in the oral carcinogenicity seen with betel. Esophageal and liver cancer have also been reported in limited numbers of betel users.
  • Avoid if allergic to betel nut or other plants of the Palmaceae family. Avoid with a history of asthma, Huntington’s disease, urinary incontinence, mental illness, chest pain (angina), blood pressure disorders, irregular heartbeat (arrhythmia), heart attack, diabetes, kidney disease, low calcium levels, cancer, or thyroid disease. Avoid if pregnant or breastfeeding. Ingestion of 8-30 grams of areca nut at once may be deadly.
  • Ginseng
    : For more than 2,000 years, the roots of this slow-growing plant have been valued in Chinese medicine. A small amount of research using ginseng extract G115® (with or without multivitamins) reported improvements in patients with fatigue of various causes. However, these results are preliminary, and studies have not been high quality.

  • Avoid if allergic to ginseng or other plants in the Araliaceae family. There has been a report of a serious life-threatening skin reaction, possibly caused by contaminants in the ginseng formulation.
  • Iron
    : Iron is an essential mineral and an important component of proteins involved in oxygen transport and metabolism. Ferrous sulfate may improve symptoms of fatigue, primarily in women with borderline or low serum ferritin concentrations. Further research is needed to confirm these results.

  • Iron is a trace mineral, and hypersensitivity is unlikely. Avoid if allergic to products containing iron. Avoid excessive intake. Avoid iron supplements with blood disorders that require frequent blood transfusions. Use iron supplements cautiously with a history of kidney disease, intestinal disease, peptic ulcer disease, enteritis, colitis, pancreatitis, hepatitis, alcoholism, or with a history of heart disease. Use cautiously if planning to become pregnant or if older than 55 years of age. Pregnant or breastfeeding women should consult a healthcare professional before beginning iron supplementation.
  • L-carnitine
    : There are several promising reports on the use of L-carnitine for fatigue. However, additional study is warranted in this area.

  • Avoid if allergic to carnitine. Use cautiously with peripheral vascular disease, high blood pressure, alcohol-induced liver cirrhosis, or diabetes. Use cautiously in low birth weight infants and individuals on hemodialysis. Use cautiously if taking anticoagulants (blood thinners) or drugs that lower blood pressure (beta-blockers or calcium channel blockers). Avoid if pregnant or breastfeeding.
  • Physical therapy
    : Physical therapy has been suggested as a possible treatment for fatigue. It is used to improve mobility, restore function, reduce pain, and prevent further injury by using a variety of methods, including exercises, stretches, traction, electrical stimulation, and massage. Special tools, such as hot or cold packs, crutches, braces, treadmills, prosthetics, compression vests, computer-assisted feedback, lasers, and ultrasound, are used. There is inconclusive evidence on whether physical therapy may help reduce cancer-related fatigue. Additional study is needed in this area.

  • Not all physical therapy programs are suitable for everyone, and patients should discuss their medical history with their qualified healthcare professionals before beginning any treatments. Based on the available literature, physical therapy appears generally safe when practiced by a qualified physical therapist. Physical therapy may aggravate pre-existing conditions. Persistent pain and fractures of unknown origin have been reported. Physical therapy may increase the duration of pain or cause limitation of motion. Pain and anxiety may occur during the rehabilitation of patients with burns. Both morning stiffness and bone erosion have been reported in the physical therapy literature, although causality is unclear. Erectile dysfunction has also been reported. All therapies during pregnancy and breastfeeding should be discussed with a licensed obstetrician/gynecologist before initiation.
  • Sandalwood
    : Endemic in Indonesia, Australia, and the Indian peninsula, the Santalum album tree is the primary source of sandalwood and sandalwood oil. Both are used in Hindu religious ceremonies. Sandalwood is also a popular fragrance for incense and perfumes. Preliminary research indicates that sandalwood oil may increase alertness. However, more research is needed in this area.

  • Avoid if allergic or hypersensitive to sandalwood (Santalum album), its constituents, or related members of the Santalaceae family. Avoid if pregnant or breastfeeding.
  • Selenium
    : Selenium is a mineral found in soil, water, and some foods. Although it has been suggested that selenium may improve symptoms of fatigue, further research is needed to draw a firm conclusion in this area.

  • Avoid if allergic or sensitive to products containing selenium. Avoid with a history of non-melanoma skin cancer. Selenium is generally regarded as safe for pregnant or breastfeeding women. However, animal research reports that large doses of selenium may lead to birth defects.
  • Taurine
    : Energy drinks containing taurine, along with other ingredients, such as caffeine and glucuronolactone, have been available for about a decade. Overall, these drinks have been suggested to decrease sleepiness associated with driving, increase concentration, mood, and memory, and positively affect well-being and vitality. Further study is required to examine the effects of taurine alone.

  • Taurine is an amino acid, and it is unlikely that there are allergies related to this constituent. However, allergies may occur from multi-ingredient products that contain taurine. Use cautiously with high VLDL cholesterol, hypertriglyceridemia (an elevated level of fatty acid compounds in the blood), a history of low blood pressure, bleeding disorders, or potential for mania or epilepsy. Use cautiously if taking hypolipidemic(cholesterol-lowering), hypotensive (blood pressure-lowering), hypoglycemic (blood sugar-lowering), anti-platelet, or anticoagulant (blood thinning) medications. Avoid consumption of energy drinks containing taurine, caffeine, glucuronolactone, B vitamins, and other ingredients before consuming alcohol or exercising. Use cautiously if pregnant or breastfeeding. Taurine is a natural component of breast milk.
  • Vitamin B12
    : Vitamin B12 is a water-soluble vitamin that is commonly found in many foods, including fish, shellfish, meats, and dairy products. There is some evidence that intramuscular injections of vitamin B12 given twice per week might improve the general well-being and happiness of patients complaining of tiredness or fatigue. However, fatigue has many potential causes. Well-designed clinical trials are needed before a recommendation can be made.

  • Avoid vitamin B12 supplements if allergic or hypersensitive to cobalamin, cobalt, or any other product ingredients. Avoid with coronary stents (mesh tube that holds clogged arteries open) and Leber’s disease. Use cautiously if undergoing angioplasty. Vitamin B12 is generally considered safe when taken in amounts that are not higher than the recommended dietary allowance (RDA).
  • Yoga
    : Yoga is an ancient system of relaxation, exercise, and healing with origins in Indian philosophy. Yoga has been described as “the union of mind, body, and spirit,” which addresses physical, mental, intellectual, emotional, and spiritual dimensions towards an overall harmonious state of being. Preliminary studies in humans report that yoga may improve fatigue in adults. However, better-designed studies are needed before any conclusion can be made.

  • Yoga is generally considered to be safe in healthy individuals when practiced appropriately. Avoid some inverted poses with disc disease of the spine, fragile or atherosclerotic neck arteries, extremely high or low blood pressure, glaucoma, detachment of the retina, ear problems, severe osteoporosis, cervical spondylitis, or if at risk for blood clots. Certain yoga breathing techniques should be avoided in people with heart or lung disease. Use cautiously with a history of psychotic disorders. Yoga techniques are believed to be safe during pregnancy and breastfeeding when practiced under the guidance of expert instruction. However, poses that put pressure on the uterus, such as abdominal twists, should be avoided in pregnancy.

Author Information

  • This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (


Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to Selected references are listed below.

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