There are a number of home remedies and natural products marketed to prevent the formation of scars and to minimize the appearance of old scars.
The kind of scars that people are often interested in preventing are hypertrophic scars. They're red and raised and can be painful or cause limited movement in the affected area (called contractures). Hypertrophic scars usually diminish somewhat over time.
Here's a closer look at some of the more popular remedies used for preventing hypertrophic scars.
1) Vitamin E
Vitamin E, or tocopherol, is a fat-soluble antioxidant. It's found in capsule or liquid form at drugstores, grocery stores, health food stores, and online. The oil is typically applied to the affected area.
Vitamin E has been shown to penetrate layers of the skin and reduce the formation of free radicals which can interfere with healing.
Vitamin E also influences the production of collagen, a structural protein partially responsible for the strength and elasticity of skin.
Although many people apply vitamin E oil to their skin to minimize scars and it's sometimes recommended by physicians after skin surgery, there's very little evidence that shows it helps.
In one study, vitamin E was used in the post-operative period after reconstructive surgery for people with burns. One group of people applied vitamin E, while another group applied an inert cream. After one year, there was no statistically significant difference in scar thickness, size, or overall appearance between the two groups.
Another study compared people who applied a cream to their scar with people who applied the cream with vitamin E added. Both groups used the cream twice a day for four weeks starting soon after their surgery.
Twelve weeks after the surgery, vitamin E didn't improve the scar appearance or worsened the appearance in 90 percent of people in the vitamin E group.
One criticism of the study is that too little vitamin E was used (one crushed capsule containing 320 IU of vitamin E in one gram of cream). Also, applying any substance to a wound too soon after injury can keep it from healing properly.
A localized skin rash was noted in 33 percent of people using vitamin E.
See my article on Vitamin E.
2) Onion Extract
Onion, or Allium cepa, is an ingredient in one of the most popular scar gels found in drugstores.
Onion extract has been found to have antiinflammatory and antibacterial properties and regulate the formation of collagen.
There have been three major clinical studies in the United States, however, and none have not found that it can improve hypertrophic scars.
One study found that there was no difference in redness and itchiness after one month (three times a day) of onion extract gel.
What was surprising was that people in the control group, who used a petroleum ointment, did have a significant reduction in scar redness. This was likely due to the hydrating effect of the petroleum ointment.
Another study evaluated 97 people with new or old scars who used either an onion gel or a placebo gel.
After two months, there was no difference in scar size, overall improvement, noticeable appearance, elevation, redness, and softness when assessed by physicians. When asked to assess their own scars, however, significantly more people using the onion gel thought their scars were softer and less noticeable.
3) Topical Honey
Honey has been used as a dressing for burns and wounds for centuries.
In 2006, a review of 22 clinical trials involving more than 2,000 people found that honey had antibacterial and antiinflammatory properties and could stimulate the growth of new tissue.
Many of the studies, which were conducted at the University of Waikato in New Zealand, used a type of honey called manuka honey.
Although honey is more promising as a wound dressing for skin ulcers and burns, there isn't enough evidence to suggest that it can help with hypertrophic scars.
Other home remedies often used for scars, but again without reliable supporting evidence, are aloe vera, gotu kola, vitamin C, and zinc.
Zurada JM, Kriegel D, Davis IC. Topical treatments for hypertrophic scars. J Am Acad Dermatol. (2006) 55.6: 1024-1031.