In the movie, the Red Pill offers truth at the price of suffering while the Blue Pill offers pleasant illusion... however this is only superficially accurate.
In real life, the Blue Pill offers nihilistic despair palliated by distractions.
(e.g. A life without purpose, meaning or real-relationship to anything - from-which we are distracted by mass/ social media, sex, status games, and temporary absorptions by work and leisure.)
While 'waking-up' from the controlled-dream that is modern virtual-reality will inevitably entail a short -term loss of pleasure; in fact the Red Pill operates as something more like a euphoriant; a euphoriant whose deep happiness is only delayed by the delay of 'absorption'.
(i.e. Life after the Red Pill is happier than life before the Red Pill; the awakened are happier than the dreamers... but there is a delay.)
The Red Pill must be a 'pill', because otherwise it will not work. In other words, we need to take-in the cure at a single gulp.
Like most effective pills, the Red Pill does more-than-one-thing - yet the medicine must be simple enough that it can be taken all-at-once.
Why? Because the evil pseudo-reality of The Matrix has several vital components - and The Matrix survives because if only one accepted-falsehood is destroyed, then the other accepted-falsehoods allow The Matrix to heal.
Thus, if we challenge only one aspect of the falsehood, while continuing to accept another falsehood, then we are still living in falsehood. Only when all of the foundational falsehoods are challenged simultaneously can we escape the Matrix...
The cure for The Matrix is therefore a single pill. The pill needs to have more than one action, more than one component - but these must all be taken together, must all act simultaneously.
Therefore, the components of the Red Pill must be very carefully selected - as few as possible (to fit them all into a single pill) but as many as necessary (for the pill to have a permanent effect).
There are many Red Pills on offer - and it seems that the usual effect is to return the taker to The Matrix but with the illusion that they have escaped it. These are the most dangerous 'Red Pills'; perhaps the only truly dangerous Red Pills - Fake Red Pills merely offer novel distractions but leave The Matrix intact - and safe.
(Those who talk most about themselves having-been Red-Pilled are examples of 'false-awakening': still asleep but merely dreaming that they have awoken; in-thrall to Matrix metaphysics of materialism, scientism, positivism; more-deeply engaged-by the distractions of The Matrix.)
However there are some Red Pills that have worked for some people - but their composition seems to vary...
So - in practice we do not know what is really a Red Pill until it has already-done its work; and even then, it is hard to know whether it really has worked without direct knowledge of that specific person.
In the end, to escape the chronic misery of life in The Matrix, we must self-experiment; and self-evaluate the effectiveness of each plausibly-effectual Red Pill - honestly and rigorously; and intuitively*.
(*Intuitively, because there is no valid 'evidence' outside of the assumptions of The System... What counts as evidence within The Matrix does not counts as evidence to The Awakened; and vice versa. Only that which lies outwith all systems can evaluate a system: the intuitive heart, the real-divine self...)