In contrast to the pharmaceuticals in an average medicine cabinet, herbal first-aid remedies are generally free of side effects and in many cases perform as well or even better than the commercial drugs.
Compared to the conventional medicines that are based on a single active chemical, herbs contain many constituents. In fact, some experts think that it's this synergy that makes plant medicines superior to drugs made in a lab. Because they have so many compounds acting at once, they're much less likely to cause the side effects you see when you've got a single foreign agent in the body.
Garlic (Allium sativum) is a staple in any herbal first-aid kit. It's a classic remedy for cuts and other abrasions, and modern research has confirmed its antimicrobial and wound-healing properties. Garlic extracts are also good at preventing or minimizing scars — and they're the key ingredient in the OTC scar medicine Mederma — and even work as a bug repellant.
Herbs can also outperform conventional remedies that incorporate more than one active ingredient, such as the first-aid sprays that combine a pain-relieving agent with an infection-fighting chemical, because the herb is almost always kinder to the skin. There are certainly herbs capable of doing harm, but the ones that have been used, time and time again, to treat injuries have been proven to be safe and effective (and generally side effect-free) remedies.
Most herbs contain hundreds of chemical constituents, or phytochemicals, many of which have therapeutic or medicinal value to humans. In many cases, the various constituents in an herb fit perfectly with the first-aid task at hand. For example, a burn might require pain relief as well as a reduction in inflammation and thus would be well served by an herb with both analgesic and anti-inflammatory properties, like calendula (Calendula officinalis) or chamomile (Matricaria recutita).
A cut or scrape could also use some antibacterial action, so you might use barberry (Berberis vulgaris) or tea tree (Melaleuca alternifolia), both of which can effectively relieve pain, reduce inflammation, and kill germs. Or maybe you have an injury that needs a styptic (something to stop bleeding) as well. In that case, you can reach for aloe (Aloe vera) or horsetail (Equisetum arvense).