Body odor is caused by bacteria that live on the surface of your skin. They feed on the fats found in sweat and excrete a sour smell. The secret to knowing which deodorant will perform best for you is knowing which one will neutralize your bacteria and eliminate the odor.

Deodorants keep bacteria at bay by changing the environment of your skin. Stick, or solid, deodorant makes skin more salty. Most gel deodorant is made from rocks or small crystals, which cause skin to become more acidic. Both formulas can also contain antibacterial agents that make skin an even more inhospitable place for bacteria. It is impossible to say which works better -- as each one may respond differently to your personal strain of bacteria.

Beauty writer Beth Shapouri of Glamour swears by gel deodorant. She believes that it offers more protection, though it may not be as gentle on your skin as a solid stick. Fans of gel deodorant also like it because it is less likely to leave white residue on clothing. However, some prefer stick deodorant because they feel that gel is sticky and slimy. Bottom line: Choose a deodorant that makes you feel comfortable and confident.

Deodorant blocks body odor by creating a harsh environment for bacteria. Antiperspirant takes it a step further by cutting off their food source. Aluminum particles block the pores in underarms, cutting off the ability to sweat. In recent years, controversy has arisen over a possible connection between the use of antiperspirant and cancer, though Cancer Research UK assures that "no convincing evidence" exists that antiperspirants cause breast cancer. However, deodorant is regarded by some to be a healthier, albeit less effective, alternative.

If you are not a fan of either solid or gel deodorants, explore spray or liquid formulas. Generally, these can be applied to any part of the body -- not just the underarms. Spray deodorant is sold in an upright aerosol can and liquid deodorant is often sold in a small plastic container with a plastic roller ball applicator.