Horsetail is rich in silicon, a trace mineral that plays a role in making and maintaining connective tissue. Practitioners of traditional herbal medicine believe that the anti-arthritis action of horsetail is due largely to its silicon content. The efficacy of this herb for osteoarthritis has not yet been evaluated in controlled clinical trials.

Comfrey has anti-inflammatory properties that may decrease bruising when the herb is applied topically.⁵ Comfrey is also widely used in traditional medicine as a topical application to help heal wounds.⁶Witch hazel can also be used topically to decrease inflammation and to stop bleeding.⁷ Native Americans used poultices of witch hazel leaves and bark to treat wounds, insect bites, and ulcers.⁸Horsetail can be used both internally and topically to decrease inflammation and promote wound healing.⁹

Comfrey has anti-inflammatory properties that may decrease bruising when the herb is applied topically.¹⁰ Comfrey is also widely used in traditional medicine as a topical application to help heal wounds.¹¹Witch hazel can also be used topically to decrease inflammation and to stop bleeding.¹² Native Americans used poultices of witch hazel leaves and bark to treat wounds, insect bites, and ulcers.¹³Horsetail can be used both internally and topically to decrease inflammation and promote wound healing.¹⁴

Asparagus (Asparagus officinalis), birch (Betula spp.), couch grass (Agropyron repens), goldenrod (Solidago virgaurea),horsetail, Java tea (Orthosiphon stamineus), lovage (Levisticum officinale), parsley (Petroselinum crispum), spiny restharrow (Ononis spinosa), and nettle are approved in Germany as part of the therapy of people with UTIs. These herbs appear to work by increasing urinary volume and supposedly helping to flush bacteria out of the urinary tract.¹⁵Juniper is used in a similar fashion by many doctors. Generally, these plants are taken as tea.

Horsetail has a diuretic (urine flow increasing) action that accounts for its traditional use in reducing mild edema. Although there is no clinical research that yet supports its use for people with edema, the German government has approved horsetail for this use. The volatile oils in juniper cause an increase in urine volume and in this way can theoretically lessen edema;¹⁶ however, there is no clinical research that yet supports its use for people with edema.

Anecdotal reports suggest that horsetail may be of some use in the treatment of brittle nails.¹⁷ This may be due to the high content of silicic acid and silicates in horsetail, which provide approximately 2 to 3% elemental silicon.