A jet injector uses no needles, but instead squirts the substance being
injected through a narrow orifice under high pressure, producing a fine
stream which penetrates the skin as easily as a needle. Jets are popular
with anyone who is simply scared of needles, for any reason. The jet
disperses the insulin more than a needle does, which probably results in
faster absorption. This can be an advantage or a disadvantage, and
requires careful monitoring when first used. Technique is just as
important as with needles, so jets are no more appropriate than needles
for small children. If a jet is used to avoid needles, equipment failure
forcing a fallback to needles may be traumatic. High cost is a major
factor.