No planet ever reverses in space. A retrograde is an optical effect: as Earth overtakes a slower outer planet, or an inner planet swings around the Sun, it appears to move backwards against the stars for a while.
Traditionally a retrograde planet's themes turn inward. Mercury retrograde suits rereading, repairing and revisiting rather than signing in a rush; Venus retrograde suits reconsidering values and old affections.
In a natal chart the ℞ mark simply means that planet was apparently backwards when you were born. It often describes a more reflective, individual way of using that planet — not a defect.
Use retrograde periods as an editor would: check details, return to unfinished work, build in extra time. Ordinary life does not need to stop.
Mercury retrogrades three or four times a year for about three weeks. Venus retrogrades roughly every eighteen months for about six weeks, Mars about every two years for two to two and a half months. Jupiter and Saturn spend roughly four months a year retrograde, and the outer planets nearly half the year.
Because the outer planets are so often retrograde, it makes little sense to treat their retrogrades as alarming. The most visible effects belong to the fast personal planets, whose retrogrades are rarer and break their usual rhythm.
The stations — when a planet appears to stop before turning — are often more noticeable than the retrograde itself. Around a station the planet barely moves, so its theme concentrates on one degree, and any natal planet at that degree is strongly touched.
A retrograde also produces three passes over certain degrees: once forward, once backward, once forward again. Situations that begin before the retrograde often return for revision during it and resolve after the final pass.
In a natal chart, retrograde personal planets can describe a person who processes that function privately before acting. A retrograde Mercury may think in loops and revisions; a retrograde Venus may develop unusual or independent values; a retrograde Mars may hold back before taking action, then act decisively.
Practical guidance is sober: back up files, reread contracts, confirm appointments, allow buffers in travel plans. These are good habits at any time; retrogrades simply give a reason to remember them.
If a decision cannot wait, make it carefully and move on. A retrograde is a reminder to review, not a ban on living.