Next time you’re feeling stressed, try giving some money away. Even in small doses, the power of generosity is potent. Donations to a worthy cause or acts of kindness to friends give your mind and body a boost.

Yes, the side effects of a charitable act and the power of generosity may include a better mood, lower blood pressure, and a longer life, according to studies from brain scientists and economists. You might experience a spike in serotonin and dopamine, hormones associated with happiness, and a drop in cortisol, researchers say. (You also get some tax benefits.)

Before you start using your checkbook as a prescription pad, there is one caveat. How you give money and time matters more than how much, says Sara Konrath, a social psychologist leading a research lab at the Indiana University Lilly Family School of Philanthropy.

Here’s the formula to getting the best return on giving:

1. Give a damn: The power of generosity works best when you mean it. You won’t feel the same high if you were guilted into giving by your Aunt Linda. You’ll feel 10% more satisfied giving a voluntary donation than when it is an obligation, a 2007 study from the University of Oregon found.

When you’re genuinely excited about the gift, the good feelings linger. A study by the University of Chicago Booth School of Business found that the joy of making a $5 gift lasted five days, while the effect of the more self-serving “retail therapy” faded much faster.

“People experience a kind of ‘giver’s high’ that lasts longer than the fleeting pleasure of personal spending,” says Lara Aknin, a psychologist studying well-being and social relationships.

2. Follow the money: Acts of charity are more rewarding when we can see the impact of our gifts. You will feel a deeper connection if you watch how your donation is used. Charities that send regular impact updates see more engaged, generous donors.

Read the full article about the power of generosity by Dalvin Brown at The Wall Street Journal.