CONTRACEPTIVES
NON-HORMONAL TOPICALS
Non-hormonal contraceptive topicals are another form of (short-acting) contraceptive method. They consist of gels which are inserted into the vagina prior to sexual activity. Topical contraceptives work by affecting either the chemical properties of sperm (essentially incapacitating it so that it cannot reach the egg) or those of the vaginal pH (thereby indirectly also affecting the viability of the sperm). Because their efficiency was typically not as high when used alone, non-hormonal topical contraceptives are often considered safe only in combination with other methods - usually barrier contraceptives. Recently, there has been a new product on the market (FDA approval in 2020) which is based on a pH altering mechanism and used as sole contraceptive (without additional barrier methods).
Spermicide
Spermicide (most commonly nonoxynol-9) works by disrupting the lipids making up the membrane of sperm, especially in the region of the acrosome (the socket at which the flagellum - the sperm's tail - connects to the sperm's cell body). By damaging the phospholipid bilayer (the membrane covering the cell) in this region, spermicide loosens the connection between the flagellum and the cell body of the sperm, which causes it to either become incapacitated or break off completely. Sperm cells which are damaged in such a way are no longer able to move properly and propell themselves forward through the cervix and uterus into the Fallopian tubes to fertilize the egg. Spermicide is accessible on the market as an over the counter (OTC) product without prescription. There are different forms of spermicide available, including gels, foams and suppositories (soft tablets which can be inserted into the vagina with an applicator, whereupon they turn into a gel-like substance). Taken alone, spermicide has an efficiency of about 70-80%. This is why it is often recommended in combination with barrier contraceptives such as diaphragms, which increases its effectiveness.The main drawback of spermicide is its altering effect on the vaginal flora and the epithelial cells of the vaginal lining, which can become irritated and sustain damage, making the vagina more susceptible to infections and chronic inflammation.
Vaginal pH Regulating Gel
Vaginal pH regulating gel (active ingredients lactic acid, citric acid, and potassium bitartrate) is a relatively new product (FDA approved in 2020). It is not a spermicide, though it looks and is applied in a similar manner (inserted into the vagina prior to intercourse). As the name indicates, the gel works by regulating the vaginal pH upon sexual activity. Under regular conditions (when not having sex), the vaginal pH (about 4) is quite low (acidic), which protects against pathogens such as fungi, bacteria and viruses. However, during the sexual contact, the pH of the vagina is temporarily increased due to the presence of seminal fluid, which has a pH of about 8. This is important for the viability sperm, which cannot function in very acidic environments, such as that of the vagina normally. Vaginal pH regulating gel works by maintaining the acidity of the vaginal pH upon sexual contact via the addition of highly acidic substances (lactic acid, citric acid, and potassium bitartrate). Such highly acidic environments impair components of the sperm cell membrane (such as membrane proteins), thereby causing incapacitation of the sperms within minutes and cell death shortly thereafter. Vaginal pH regulating gels are prescription products which require prescription by a healthcare provider. Without insurance, the price for the gel is at approximately $300 per box (12 applications). If used correctly, efficiency is at about 85-90%.
