My understanding is that Venus, Earth, Mars, and Jupiter are all losing mass due to their gravity, temperature, and the solar wind. But what about Mercury, Saturn, Uranus, and Neptune? Mercury has a magnetic field and so typically would repeal the worst of the solar wind and no atmosphere to lose, only an exosphere. I do not know the calculations to determine if Saturn, Uranus, and Neptune are losing mass though.
Anything that's working, spending energy is losing mass, Einstein Mass-energy equivalence of SR along with radiant energy(electromagnetic and gravitational radiation) would be effecting all the planets, but at a different rate for each one. https://en.m.wikipedia.org/wiki/Radiant_energy
And. https://en.m.wikipedia.org/wiki/Mass_in_special_relativity These should help I think