An ultrasound gel is provided for use with internal ultrasound imaging and/or therapy. The gel can have acoustic properties that can closely match a soft tissue to be imaged/treated and can be of a high viscosity that is maintained when heated by the body. In some embodiments, the gel can act as a lubricant and, although water based, can be hydrophobic and not dissolve in bodily fluids. In some embodiments, the gel can be sterile, safe for ingestion, and include a preservative. The gel can be used for oral or non-oral applications and when used orally, can comprise a dental agent for inhibiting growth of dental microorganisms and/or prevent respiratory infections.