Over the Counter & Complementary Therapies

Over the Counter & Complementary Therapies

Our understanding of Parkinson’s disease (PD) has evolved from the initial focus on motor symptoms to now include non-motor symptoms (such as, mood, fatigue, constipation) of the disease. People with PD who seek relief from their symptoms may decide to explore complementary therapies, which can support or complement traditional medicine. While there are many kinds of complementary medicine, this section focuses on herbs, vitamins and supplements.

Although there is little conclusive scientific information on natural supplements, researchers are examining several substances to evaluate their effectiveness on slowing PD progression and managing its symptoms.

Nutritional supplements are not regulated with the same approval method for prescription drugs. People with PD should discuss any medications (prescription or over-the-counter) with a doctor before taking them to avoid potentially dangerous interactions. If you are considering complementary medicine, we strongly urge you to investigate the credentials and experience of anyone offering advice or recommendations regarding such product.

Key Points

  • Most herbs and supplements have not been rigorously studied as safe and effective treatments for PD.
  • The U.S. Food and Drug Administration (FDA) does not strictly regulate herbs and supplements.
  • There is no guarantee of safety, strength or purity of supplements not monitored by the FDA.

Antioxidants: Vitamin C and E, Mediterranean Diet

Since there is evidence relating oxidative damage of nerve cells to PD, some researchers are studying antioxidants:

  • A 2002 study focused on the potential antioxidant Coenzyme Q10 (CoQ10), which is believed to play an important role in mitochondria health. Mitochondria are the "powerhouses" of a cell. Some scientists think that abnormalities of mitochondrial function may play a role in PD.

In 2011, a large clinical trial studying the potential benefits of CoQ10 on reducing the progression of early PD was stopped because a mid-study analysis suggested that there was no improvement in the people taking CoQ10 in comparison to those receiving treatment. Researchers decided that continuing the study would have shown an extremely low likelihood of CoQ10 showing any benefit in delaying the progression of early PD.

Scientists have also examined Vitamin E, Vitamin C and health foods to evaluate oxidative properties. Vitamin E can fight damage in the brain caused by free radicals and has been suggested to lower the risk of PD. However, researchers conducted an extensive and thorough study more than 10 years ago (the DATATOP trial) and failed to find any evidence that Vitamin E slows the progression of PD or manages symptoms. Since Vitamin E has few side effects, many people with PD continue to take it in high doses of 400 IU or more.

Researchers are also examining if health foods, such as fermented papaya and blueberries, play a role in slowing nerve cell death. Scientists are optimistic about the research, but do not have conclusive data to recommend these supplements to treat PD.

  • Creatine is another supplement of scientific interest. It increases levels of phosphocreatine (an energy source in muscle and brain). The National Institute of Neurological Disorders and Stroke (NINDS) conducted a multi-center clinical trial to study creatine for treatment of early stage Parkinson’s. The study was terminated early due to an interim analysis that did not reveal a significant different between creatine and a placebo.

Researchers have also studied a compound called glutathione to determine its effect on nerve cell metabolism and its power as an antioxidant. Both compounds show promise, but appropriate dosing is unclear, as are the most effective administration method, side effects and long-term dosing risks.

Vitamins C and E

Free radicals are toxic molecules produced by virtually every cell in the body, usually in response to stress or injury. For example, sunlight exposure, cigarette smoking and infection can generate free radical formation in some cell types. These particles are thought to be particularly toxic to brain cells. Antioxidants “soak up” free radicals. Vitamins C and E are antioxidants that fight free radicals and may protect brain cells.

  • Some concerns have been raised about possible side effects of Vitamin E supplements, particularly the form of Vitamin E commonly available (alpha-tocopherol). A “mixed” supplement, containing multiple forms of Vitamin E may be safer or more effective.
  • Good dietary sources include whole grains, wheat germ, avocados, nuts and vegetable oils.
  • Since there is evidence that free radical damage is involved to some extent in PD, Vitamin E, was studied in people with early PD in a large study in the 1980s. The study did not show an effect on disease progression or neuroprotection. Instead it showed that it could potentially be harmful to people with PD and that it is possible that dietary Vitamin E is used more easily by the body than the supplements in the study, however more research is required.

The Mediterranean Diet

  • There is some evidence that the Mediterranean diet, a diet high in monounsaturated fats, such as olive oil, may be beneficial in reducing blood pressure and cardiovascular disease.
  • The diet also emphasizes fish, especially those high in Omega-3 fatty acids, such as salmon and foods containing antioxidants.
  • People with PD are often concerned about the possibility that protein intake can decrease the effectiveness of carbidopa/levodopa, the common medication used to treat PD. Levodopa absorption in the brain can be slowed by a high protein meal. As the disease progresses, most people find their symptoms are better controlled if they consume their protein later in the day.
  • Since PD can affect digestion, many people will notice symptoms such as constipation and early satiety (the sensation of feeling full after consuming a small amount of food).


Getting enough calcium can be difficult for people with PD as many find dairy foods more likely than other protein foods to inhibit levodopa absorption. Here are some recommendations that will help you meet your calcium requirements:

  • Drink calcium-fortified orange juice
  • Add calcium-fortified-rice and soy milk alternatives to cereal, smoothies and cooked dishes
  • Switch to breakfast cereals and other foods fortified with calcium
  • Consider taking a calcium supplement — calcium citrate is often a better choice.
  • Chewable calcium tablets are better absorbed since they are already broken down when they reach the stomach.

Vitamin D

  • The current recommendation for vitamin D is 600 IUs for people age 50 or older, and 800 IUs daily for those over the age of 70.
  • The body cannot absorb calcium without adequate amounts of vitamin D.
  • If you live in a sunny area, vitamin D is easy to absorb. Spend about one hour per week outdoors in the sunshine, but wear sunscreen.
  • Because vitamin D is stored, our bodies can conserve enough in the summer to last through winter.
  • If you do not live in a sunny area or prefer to stay indoors, here’s how you can eat to get the amount you need:
    • Fortified foods such as milk and milk substitutes, milk products, margarine and cereals
    • Fatty fish, such as salmon and fish liver oils
    • Liver
    • Eggs

Coenzyme Q-10

Cells need energy to survive and function. They contain mitochondria, which are “batteries” that produce energy. In PD, there seems to be a disturbance in the function of these batteries. Coenzyme Q10 seems to affect this energy-generating mechanism in cells. The exact mechanism remains a mystery.

A trial sponsored by NIH and the Parkinson Study Group was terminated in May 2011 because it showed no neuroprotective or symptomatic benefit of Coenzyme Q10 for people with early PD. However, this negative finding may help scientists focus on possible mechanisms and more promising drugs and studies. Findings of this study are specific to PD. They do not reflect the possible value of coenzyme Q10 in other disorders.

Ginger (Zingiber Officinalis)

Ginger in almost any form is excellent for nausea and vomiting, whether the nausea stems from something as simple as motion sickness or as a side effect of medications. Fresh ginger root, available in the produce section of most grocery stores and markets, can be prepared as a liquid. It can also be taken in other forms:

  • Cover a one-inch slice in water, bring to a boil and simmer for 30 minutes.
  • Ginger is sold in health food stores as a liquid. A drop or two can be added to tea or other beverages.
  • Nibble small pieces of crystallized ginger, available as a cooking spice, at the first sign of queasiness.
  • A Japanese study using a mouse model of PD, found that zingerone, a compound found in ginger root, may have a protective effect on dopamine-containing neurons.

Folate (Folic Acid)

  • Folate (Vitamin B9) is another vitamin that is important for brain health and good memory.
  • Vital for the development of the nervous system and insuring adequate amounts during pregnancy can prevent certain types of birth defects.
  • Folic acid, along with B12 and possibly B6, can decrease levels of homocysteine, which may prevent strokes and heart attacks and help memory as well.

Green Tea Polyphenols

  • Green Tea Polyphenols (GTP) have antioxidant and free radical scavenging activities.
  • Some studies have suggested that these compounds could have a neuroprotective effect and possibly even a treatment effect in PD.
  • The Chinese Ministry of Health and the Michael J. Fox Foundation, with the assistance of Dr. Caroline Tanner of the Parkinson’s Institute and Clinical Center, a Parkinson’s Foundation Center of Excellence in Sunnyvale, CA, conducted a study to evaluate GTPs ability to slow disease progression and its safety and tolerability in Early PD. After one year, there was no significant difference between those who took GTP or a placebo. There was a change noted in the total UPDRS score in the “delayed-start” group from 6 months (began GTP) to 12 months, suggesting there may be a slight benefit. However, additional research is needed particularly to understand the dose effect. Insomnia was slightly increased in the GTP group, suspect this is related to the caffeine content.

Caution: Green tea products contain caffeine. Take this into consideration when using them.

Milk Thistle (Silybum Marianum)

  • Many drugs and environmental toxins are processed through the liver. Milk thistle has been used to treat disorders of the liver and gallbladder for at least 2,000 years.
  • Research shows that the silymarin in milk thistle helps protect the liver from many industrial toxins, such as carbon tetrachloride.
  • There is also evidence that compounds from milk thistle seeds help protect the liver against damage from alcohol and hepatitis and can even regenerate damaged liver cells.
  • Helps improve liver function by helping to remove toxins from the body.
  • In his book, The Brain Wellness Plan, neurologist Dr. Jay Lombard advises people with PD who take anti-Parkinson’s drugs (metabolized through the liver) to add 300 mg of standardized milk thistle extract to their daily medication regime.
  • Available in capsules.
  • The compound appears to be safe, although more testing is needed to determine if there are any negative long-term effects. There are no published studies of milk thistle in the treatment of PD.

St. John’s Wort (Hypericum Perforatum)

  • Herbal supplement is a popular anti-depressant, working in a pharmacologic manner similar to the prescription selective serotonin reuptake inhibitor (SSRIs).
  • May be effective in mild to moderate depression, but two studies reported no benefit in major depression.
  • The most frequently prescribed antidepressant medication in Germany. The most common dose being 300 mg, three times daily.
  • Although Hypericum Perforatum is one substance known to be present in the flowers and leaves of this plant, it also contains other unidentified compounds that appear to be active.
  • In one study of Hypericum Perforatum in a mouse model of PD, there appeared to be some inhibition of the effect of the toxin (MPTP) used to cause Parkinsonism.


  • St. John’s Wort may interfere with certain PD medications, most particularly MAO-B inhibitors.
  • St. John’s Wort should not be used concurrently with other antidepressant medications. People taking Prozac, Zoloft, Paxil or other SSRIs risk serious overdose effects by using Hypercom.
  • St. John’s Wort should not replace traditional prescription medicine for the treatment of a serious or major depressive episode.
  • Do not take St. John’s Wort if you take blood thinners such as aspirin, heparin or warfarin (Coumadin).
  • People with PD who also take asthma medications, steroids, birth control pills, cough medicine, digoxin, immunosupressants, HIV medications, triptans (used to treat migraines) should consult their physicians or health care providers before taking St. John’s Wort.
  • Do not drink alcohol while taking St. John’s Wort.

Vitamin B12

  • Important factor in brain and nerve health, especially memory.
  • Dietary Vitamin B12 is found in animal protein sources such as meat, eggs, fish and dairy products.
  • As people age, they may develop difficulty absorbing B12 from the gut, even if the amount in their food sources is adequate.
  • Oral supplements (usually 1000 mcg) may help, although persons with severe B12 absorption problems or deficiencies may require injections.
  • Vegetarians may also develop a B12 deficiency.
  • A chemical called homocysteine can become elevated in people with PD, often in conjunction with levodopa therapy. There is an unproven theory that the elevation of homocysteine may be related to memory loss in some cases. Increasing B12 and folic acid will often result in a decrease in homocysteine levels, though it is not yet known whether this will improve memory.

Over-the-Counter (OTC) Medications

Although nutritional supplements have shown some promising results in preliminary studies, it is important to remember that there is not sufficient scientific data to recommend them for Parkinson’s. OTC medications have side effects and interactions with other drugs. They tend to be expensive and vary with different manufacturers. Before taking any OTC medication, a person with PD must discuss adding these supplements with their doctor.


It is important for people with Parkinson’s to let their health care providers know of any herbal products, vitamins, over-the-counter medications and dietary changes they have made on a regular basis. Some of these compounds may interact or interfere with PD medications.

Read more at the National Center for Complementary and Alternative Medicine web site.

Page reviewed by Dr. Chauncey Spears, Movement Disorders Fellow at the University of Florida, a Parkinson’s Foundation Center of Excellence.


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