What are Syndets?

Have you heard of syndets? Are they a new buzzword, the latest and greatest cleanser, or a niche product for a special interest group, or perhaps just a brand name?

You may have heard of the term “syndets” in recent years if you follow skincare, and wondered if it’s something you need to know about, or just another buzz word that comes and goes. Syndets are a portmanteau of “synthetic” and “detergent.” Although synthetic detergent doesn’t sound particularly appealing (probably why the cosmetic industry chose to create a new word to promote), it has several advantages over the traditional soap.

No Soap Scum:

Soap scum, the gunk that can be seen in the bathtub if it hasn’t been cleaned in a while, is the remnant of the soap that is not effectively dissolved. It is often seen in bathtubs, as a white solid that covers the tub. This is caused by traditional soap which reacts with metal ions that are often found in hard water, forming the soap scum which doesn’t efficiently dissolve. While they are generally harmless, it is thought that vinyl shower curtains should be cleaned periodically as the soap scum can contain a microbial film which may carry pathogenic bacteria.

Synthetic detergents have an advantage in that they are not nearly as susceptible to reactions with metal ions, and can lather easily on all water. This property is used effectively in hair care products like shampoos and conditioners, as nobody would enjoy soap remnants stuck in their hair.

Flexible Formulation:

Syndets are flexible in its formulation, being able to choose from a larger pool of potential ingredients. Soaps are made by mixing fatty acids with a base in a process called saponification, and are generally more limited in the ingredients that it can incorporate. Synthetic detergents are used in a variety of ways outside of skincare:

  • Laundry detergents
  • Dishwashing liquids
  • Shampoos and conditioners
  • Fabric softeners
  • Car shampoos

Dermatologist Dr. Charles Lynde explains dry skin in this video, and explains the role of new syndets that combine moisturizers and cleansers: