No matter how hard you work out or how smart you are about your diet, there may be an area that could use improvement. From boosting cardio performance and accelerating strength to recharging energy, these ingredients— and the supplements you can find them in—help you get the results you want.

What it is: DHEA stands for dehydroepiandrosterone, a hormone produced naturally in both males and females mainly by the adrenal glands, as well as the gonads, the gastrointestinal tract and even the brain. DHEA is the most prevalent hormone circulating in the body. That’s because DHEA gets converted into about 20 different hormones, with the two main end products being testosterone and estrogen.

Why it’s great for women: DHEA is usually thought of as a male hormone, yet women can experience similar benefits from DHEA supplements as men, which includes better energy, greater brain function, better moods, increased strength and muscle mass, and enhanced fat loss. This is due to an increase in testosterone and insulin-like growth factor-1 levels (IGF-1) in women, which was shown in two separate studies using 100mg of DHEA per day from the University of California, San Diego and the Tel Aviv University (Israel). The Israeli scientists reported that this led to an increase in women’s sexual arousal and cognition. Although both studies used older postmenopausal women, similar results should be expected in younger women since DHEA levels begin to drop after 25 years of age. Since testosterone and IGF-1 are important for muscle strength and hypertrophy, supplementing with DHEA may be a safe way to naturally boost you testosterone and IGF-1 levels slightly without adverse effects.

How to take it: Take 100mg of DHEA daily with meals.

What it is: Iron is a mineral that is a part of numerous proteins and enzymes important for good health. In addition, as a component of red blood cells, it helps deliver oxygen to our cells.

Why it’s great for women: Intense training lowers iron levels. Studies confirm that numerous female athletes are iron deficient, which leads to a reduction in performance, increased fatigue, decreased cognitive function, and impaired immune function. This appears to be due to an increase in hepcidin (a hormone produced by the liver that inhibits iron absorption) with exercise. French researchers recently found that in almost 200 women between the ages 18–53 who complained of fatigue, those taking 80mg iron daily for 12 weeks had a 50% reduction in fatigue. Army researchers also reported that women taking 100mg of iron during eight weeks of basic training had higher scores for cognitive performance and faster times in a two-mile run test.

How to take it: Because iron toxicity can occur if you are not iron deficient, you should consider asking your doctor for a serum ferritin test to measure your iron status. If you are low, taking 30–100mg daily without food can help depending on how low you are. Since exercise decreases iron absorption, take iron supplements several hours before exercise if you train later in the day, or several hours after exercise if you train early.

What it is: Caffeine is the world’s most popular stimulant, thanks to the fact that it exists naturally in coffee beans and tea leaves.

Why it’s great for women: Sure, we all could use a cup of joe to wake us up first thing in the morning, but caffeine offers benefits beyond its stimulating properties. It is one of the most studied ergogenic aids and has been shown to be effective for booting muscle strength, muscle endurance, and mental focus. Caffeine’s specific benefits for women are its ability to suppress the cognitive decline that occurs with aging as discovered in a 2010 study in the Journal of Alzheimer’s Disease (the study showed no such protective effect of caffeine for men). This study lends further support to a 2007 study by French researchers showing a similar neuroprotective benefit of caffeine in women. Finally, a 2011 study from Harvard that tracked women for almost 20 years, suggested that women who consumed the highest caffeine levels (mainly from coffee or tea) were 20% less likely to become depressed as those who consumed little to no caffeine. An earlier published study from Harvard also found a slight association between caffeine consump- tion and a reduced risk of breast cancer. This may be due to caffeine’s ability to reduce estrogen levels, as discovered by the National Institutes of Health, possibly through higher sex- hormone binding globulin (SHBG) levels.

How to take it: Take 100–200mg of caffeine as needed daily, with typical times being morning and before workouts. While coffee may be a fine way to get your morning pick-me-up and provide some health benefits, caffeine in supplement form (mainly caffeine anhydrous) is what’s been found to provide the real performance benefits.

What it is: Calcium is a mineral needed for numerous functions in the body, from bone health to muscle contraction.

Why it’s great for women: This one seems like a no brainer since every woman is drilled to get in plenty of calcium for healthy bones. That’s important, but we’re not suggesting it for bone health. Fat loss, you say? Sure, there may be an association between calcium intake and body-fat levels, but both bone health and body fat are two benefits that men also derive from calcium. The real reason we are suggesting you take it is for benefits that men won’t get—reduced PMS symptoms. Several studies have reported an inverse relationship between calcium intake and PMS, so the higher the calcium intake, the fewer the PMS symptoms. One study by Iranian researchers reported that women suffering from PMS who took 500mg of calcium twice a day for three months had a significant reduction in fatigue, appetite changes, and depression compared with those who got a placebo.

How to take it: Every woman should supplement with 1,000–1,200mg of calcium per day, regardless of whether or not you suffer from PMS. Your best bet is to take at least two doses for enhanced absorption of calcium. To further promote calcium absorption, also take each dose with between 500–2,000 IU of vitamin D. A recent study from the University of Massachusetts suggested that vitamin D intake is associated with fewer PMS symptoms, although this is likely due to higher calcium uptake. For a great calcium supplement check out Twinlab Calcium Citrate, which is one of the most absorbable forms of calcium.

For a good vitamin D supplement check out Futurebiotics Vitamin D3.