Along with Venus, Neptune is a planet of feminine energy. As the modern ruler of Pisces, she symbolizes what's ideal, noble, transcendent, nebulous, and spiritual in our lives. She is how we experience a sense of unity and sympathy with the world. However, she also represents how we encounter illusion, delusion, addiction, and loss.

Neptune takes it's time to move through the zodiac, spending roughly 14 years in each sign. Because of this snail's pace, the effects of the transit may be subtle and reveal themselves only over time, or when Neptune makes significant aspects to the natal chart. Neptune stations retrograde only once a year, spending nearly half of the year there, as these retrograde cycles normally last between five to six months.

NEPTUNE RETROGRADE MEANING
If you were to chance upon a text regarding Neptune's role in astrology, you would likely be inundated with its soft-touch spiritual themes, ranging from its ability to inspire heady artistic visions as well as pitch us into mystical whirlpools of healing. In part, this is true: Neptune has a nebulizing effect that can snap us out of our ego-identities just long enough to let a little universal love pour in.

There is much more to Neptune, however, and not all of it so rosy.
In the foggy realms of Neptune, boundaries tend to disappear altogether, leaving us open to deception and delusions. While part of Neptune's tendency is admirable, in so much it generates a well-intentioned desire to serve without reward, the danger with planet Neptune is to dissolve entirely into the 'other,' sacrificing our ego-identity as we search for salvation.

If Uranus seeks what's new while Pluto seeks what lies beneath, Neptune seeks the ideal. The placement of Neptune in the natal chart by sign, house, and aspect can describe an area of life where we seek to be redeemed from the disappointing reality of human existence. This process is usually unconscious—by throwing ourselves into work or relationships past all point of separation, we may be seeking much more than a happy marriage or a pay raise.

Somewhere deep down, we may believe that this area of life will lead us to deliverance and that by sublimating our personal, ego-based needs to the greater good, we will somehow manage to atone for our sins and be welcomed back into Eden.

Neptune also involves a fair amount of fantasy. There's something of Dionysus in Neptune: music and dance, diversion and indulgence converge into one, leading us from this plane of existence into sacred, non-linear consciousness. As a higher octave of planet Venus, highly personal affections of romance are transmuted by Neptune into collective, unconditional love.

NEPTUNE RETROGRADE EFFECTS
Being the Master of Illusion means working in mysterious ways. The fact that it is retrograde about 40% of the time, also means that Neptune's effects are subtle, and even sneaky—very sneaky. When direct, Neptune will put a veil on our eyes, helping us hide anxieties and unwanted realities. Once it is retrograde, Neptune loses its powers, and this illusion is slowly but surely stripped away; sometimes leaving us face-to-face with a harsh and painful reality. The rose-colored filters are gone, and we must face reality.

Neptune has been called the Greatest Malefic, perhaps because we do not see her coming until she is there. But ultimately, Neptune retrograde can help us find deeper meaning, not only in our dreams, but also in our entire existence.
Because Neptune moves through the zodiac so slowly, transits from Neptune to a natal planet may last several years. This is one key reason the Neptune retrograde transits are important—very easily, Neptune transits can dominate entire years of our lives. If one of our natal planets is caught in the cross-hairs of Neptune's retrograde stations, the effects may be particularly intense and long-lasting.

NEPTUNE RETROGRADE IN THE NATAL CHART
Since Neptune spends roughly one half of the year in retrograde, there's a good chance you may have Neptune retrograde in your birth chart.

Retrograde planets in the birth chart are sometimes described as being unable to fully express themselves or having oddball, round-about ways of manifesting their influence. Just as common is the idea that retrograde planets in the natal chart only begin to emerge successfully later in life after much introspection and adjustment.
In traditional astrology, however, retrograde planets are not seen as merely misguided, but as being thoroughly weakened. Speed and visibility were both important considerations to ancient astrologers, and on both accounts, retrograde planets are at a disadvantage. Fast-moving planets were interpreted as being active and able to bring about their significations, while slow-moving planets, like ones in retrograde, were deemed too sluggish to do their job properly. It is worth noting that the outer planets Uranus, Neptune, and Pluto, had not yet been discovered when the ancient astrologers were drafting their opinions on retrograde planets.

In general, Neptune retrograde in the natal chart is considered less impactful than a retrograde personal planet, such as Mercury or Venus. The effects of natal Neptune retrograde gain more potency if Neptune forms strong aspects to other planets or points, particularly the sun, moon, and ascendant.

A prominently placed Neptune, whether direct or retrograde, may give one a dreamy countenance and a natural affinity to otherworldly landscapes. Neptunian types are normally highly empathetic and empathic, qualities which can open ripe channels of creative expression. With such a marked sensitivity, however, a prominent Neptune in the natal chart can lead some to escapist behaviors in response to the constant influx of stimuli and energy they experience.

Taken to the extreme, this may mean checking into the local ashram and renouncing all connection to the material sphere, while others may find themselves tripping the light fantastic as they attempt to meet God through song and dance. A rare but persistent connection between Neptune and celebrity abounds; those with Neptune in helpful aspects to their sun, moon or ascendant may have no trouble attracting the limelight.

Neptune retrograde in the natal chart may make those with this placement less aware of their spongey, boundaries-less existence. There may be a deeply subconscious, persistent desire to sublimate one's self and needs to whoever (or whatever) they have currently enthroned on the pedestal. After substantial Neptunian setbacks, including but not limited to addictions, delusions, and deception, those with Neptune retrograde may be forced to negotiate their relationship to self-sacrifice and refortify their ego boundaries.

Eventually, Neptune retrograde can become a source of inspired compassion and oneness.

https://www.astrology.com/retrograde/neptune-retrograde