•A new set of dose response equations fit data where X is dose or concentration, to complement the existing set of equations where X is the logarithm of dose or concentration.

•Faster. When you choose a built-in equation, nonlinear regression is more than ten times faster than it was with Prism 6, with improved precision. This is because the derivatives (and second derivatives) are now evaluated analytically rather than numerically. This will even work when you clone a built-in equation and change parameter names.  This extra speed is noticeable when you have lots of data, do Monte Carlo simulations, ask for Hougaard's measure of asymmetry, or ask for asymmetric likelihood confidence intervals (which require more computation).

•The rules for initial values have been improved for the parameter Width in the log(Gaussian) distribution, for all three parameters in the equation for enzyme substrate inhibition, and for the Amplitude of a sine wave.

•New equation for sine wave with nonzero baseline.

•Renamed "One-site --- specific binding with Hill slope" equation to "Specific binding with Hill slope", because with a Hill Slope that doesn't equal 1.0, this equation really necessarily describe binding to one site.