Which supplements help to improve energy and decrease fatigue?

Answer:

Getting adequate sleep, eating a healthy, well-balanced diet, and regular exercise are the best ways to maintain your energy. However, we all have times when we could benefit from an energy boost. (If you are frequently tired, be sure to consult your physician about potential causes, as discussed below).

Certain supplements may help increase energy and decrease fatigue:
(Use the links below for more information about each supplement, including ConsumerLab's test-based reviews and Top Picks among marketed products.) 

CoQ10, which plays a role in energy production in cells, has been shown to decrease fatigue in people with conditions such as heart failure and Gulf War Illness. One small study suggested it may increase self-assessed "vitality" in older adults. (Be aware that taking CoQ10 in the evening can cause insomnia in some people).

Curcumin (from turmeric) has been shown to reduce fatigue in older men and women using a particular branded formula.

Ashwagandha may reduce fatigue in middle-aged adults with moderate to severe anxiety.

Cocoa flavanols may help reduce self-reported mental fatigue in healthy adults, according to one study.

Ginseng is a popular ingredient in supplements promoted for increasing energy and vitality. Although there is little evidence to support this effect in healthy people, there is some evidence it may increase energy in people with cancer-related fatigue.

Carnitine may help reduce fatigue in older men with symptoms of sexual dysfunction, depression and fatigue.

B vitamins are involved in the metabolism of food to release energy, and deficiency in vitamin B-12 is known to cause fatigue. However, if you already get an adequate amount of the B vitamins in your diet and are not deficient in them, supplementing with additional amounts of B vitamins is not known to improve performance. Be aware that energy drinks often contain much higher doses of B vitamins than needed — sometimes amounts above tolerable limits. Energy drinks also commonly contain significant amounts of caffeine or ingredients which naturally contain caffeine such as guarana and cola nut. Although caffeine does not actually provide energy, it acts as a stimulant and can reduce fatigue. Be aware that energy drinks can increase blood pressure, and stroke and liver injury have been reported in people consuming certain energy drinks.

One of the early signs of magnesium deficiency is fatigue (others are weakness, loss of appetite, and nausea). Increasing magnesium intake from foods or a supplement, can reverse this.

Energy bars, or nutrition bars, can be a good source of real energy (calories), especially if you are on the go and haven't had a chance to eat a real meal, and also provide vitamins and minerals. It's important to choose carefully as some are high in sugar, or contain sugar substitutes that may upset your stomach. Some also contain caffeine.

Supplements that provide iodine, such as kelp supplements and potassium iodide, are often promoted to increase energy. However, there is little evidence for this effect unless they are being used to treat hypothyroidism due to iodine deficiency.

Rhodiola rosea and maca supplements are sometimes promoted to increase energy or reduce fatigue, however, there is not enough evidence to support these supplements for this use.

Iron deficiency can cause fatigue. Consequently, correcting iron deficiency with iron supplementation can reduce related fatigue. Interestingly, iron supplementation has even been shown to reduce fatigue in women who are not anemic but have ferritin levels in the lower end of normal range.

If your fatigue is caused by difficulty sleeping, melatonin or other supplements for sleep may be helpful. (Note that taking high-dose vitamin D may reduce your body's natural production of melatonin).

A supplement that can cause fatigue:

Be aware that St. John's wort can cause fatigue when you take it, or if you abruptly stop taking it.

Because there are many possible causes of fatigue, it's important to consult with your doctor if you feel tired frequently.