Humulus lupulus (hops) [CO2] extract
What is it?
The hop plant is a perennial herb that grows in vines. Native to Europe, Western Asia, and North America, it is known for the speed and persistence of its growth. Most people are familiar with hops because of its role in beer-making, although it also featured in ancient kitchens and the medical recipes of herbalists. First widely used in beer by monks in 9th- and 10th-century Germany, the hop didn’t gain popularity because of its flavor. Instead, the “bitter principles” of hops exhibit antimicrobial behavior, making the ingredient an effective preservative and stabilizer. In 1516, Wilhelm IV, lord of Bayern, ordered that hops be one of the required ingredients in beer in his Reinheitsgebot (Purity Law). That law led to similar enactments in other countries and helped to standardize the use of hops in brewing. Hops’ distinctive bitterness has now become one of the familiar attributes of a typical beer. Only the female flowers, known as cones, are used in beer-making. For our deodorants, we use hop resins extracted from the cones with carbon dioxide (CO2). The CO2 is obtained from natural sources which are found in the German volcanic Eifel, a region which is also famous for sparkling mineral waters. This volcanic CO2 comes slowly to the surface by diffusion. Using a natural source prevents the release of additional CO2 into the environment and allows us to have all the benefits of this gentle, natural and clean extraction technique in a climate-sensitive way.
What does it do?
Unpleasant odor is caused by skin bacteria when we sweat. The “bitter principles” that help hops to preserve beer also, it turns out, fight odor. Our research team has shown that our hops extract inhibits the growth of odor-causing bacteria (J Cosmet Dermatol. 2009, 8: 197-204). Hops acts by causing leakage in the bacterial cell membrane, which impairs bacterial function and therefore prevents odor formation. In addition, our special combination of hops and chamomile CO2 extracts used in the Natural Sensitive Deodorant Sticks has been tested in a clinical study for its soothing properties. We use hops in our Natural Original Deodorant Sticks, our Natural Sensitive Deodorant Sticks and our Natural Long-Lasting Deodorant Sticks.
How is it made?
What are the alternatives?
Lichen (Usnea barbata) has been in our (and many other natural) deodorants since 1991, and it provided effective and natural odor protection. However, a minor percentage of the general population—often, those who tend to have fragrance allergies—may experience a skin reaction to lichen. Even though it's a relatively uncommon reaction, we weren't satisfied, and our scientists continued to search for ingredients with less irritancy potential. We also felt increasingly uncomfortable with the environmental drawbacks to using lichen. Studies have shown that the large-scale harvesting of lichen may not be sustainable given its long regeneration rates.
Is this the right option for me?
Hops are believed to have sedative properties, but topical application in the amount found in our deodorant will not cause sleepiness.
Tom's of Maine recognizes that no two people are alike, and even with naturally derived ingredients, some individuals may develop an allergic reaction that is unique to them. As with any product, be sure to discontinue use if you experience discomfort or other indications that the product may not be appropriate for your individual body chemistry.