There are hundreds of methods of meditation, but perhaps Vipassana has a unique status; just the same way as there have been thousands of mystics, but Gautam Buddha has a uniqueness of his own. In many ways he is incomparable. In many ways he has done more for humanity than anybody else. In many ways his search for truth was more sincere, more authentic than anybody else's.
The meaning – the literal meaning – of the word Vipassana is "to look," and the metaphorical meaning is "to watch, to witness."
     Gautam Buddha has chosen a meditation that can be called the essential meditation. All other meditations are different forms of witnessing, but witnessing is present in every kind of meditation as an essential part; it cannot be avoided. Buddha has deleted everything else and kept only the essential part – to witness.

     When you have become perfectly watchful of your body, mind and heart, then you cannot do anything more, then you have to wait. When perfection is complete on these three steps, the fourth step happens on its own accord as a reward. Suddenly your life force, your witnessing, enters into the very center of your being. You have come home.

Osho The Rebel

When I do Vipassana meditation I become drowsy and have low physical energy. Mostly when doing Osho Dynamic I feel pretty good.
     Pretty good?
     My feeling is that at least for six to nine months you should do Osho Dynamic meditation. Your energy seems to be low. The Osho Dynamic meditation will help the energy to rise higher. Only then will Vipassana be helpful. Otherwise this happens: energy is low, Vipassana brings it even lower, because it is a very silent process. Then wherever energy is too low you will feel drowsy, sleepy, and you may start dreaming, and then the whole point is lost.
     Vipassana can be done only when the energy is very high, so high that even if Vipassana brings it low, it cannot bring it so low that you start feeling drowsy. Otherwise in Buddhist monasteries that is almost the normal routine: out of one hundred monks, ninety-nine are drowsy, sleepy. That's why the Zen master has to move with a stick to hit their heads: they are all drowsy! In fact it is natural. It is not their fault! They have to get up at three o'clock, early in the morning, and then start meditating; and it continues the whole day. Unless somebody really has very high energy, he will fall into sleep.
     So my approach is: first bring the energy to such a high level that even when you do Vipassana.... It will go down a little: your heart-beat will be slower, your pulse will be slower, your blood circulation will slow down – everything slows down in Vipassana. So in Vipassana you will fall asleep; it will not be of any use to you.
     For nine months concentrate on Osho Dynamic meditation, and after nine months start Vipassana.

Osho Won't You Join the Dance?

I was doing a Buddhist meditation for two years.... I kept falling asleep!
     The whole method is so silent, so relaxing, that the natural possibility is to fall into sleep. Whenever we relax, whenever we are silent, we fall asleep, so with relaxation there is a deep association with sleep.
     That's what we have been doing for our whole life...and the Buddhist meditation depends on relaxation. So once you relax, the mind gets the hint that now you are ready to sleep, because that is the only way it has come to know sleep. It has no other way, no other experience. It cannot figure it out: if you are relaxed, why aren't you going to sleep?

     To fall asleep, relaxation is a must, but relaxation is not necessarily a step towards sleep. It can become a step towards meditation too. But then a great change of your past associations is needed; otherwise you will fall asleep. But it is good that you tried. With my meditations it will never happen because they are so active. They create a turmoil in your energy, a chaos; you cannot fall asleep. And for the modern mind, that seems to be the best possibility.
     In the old days when Buddha was here and when he invented his meditations, people were absolutely relaxed. In India in those days – all over the world in those days – people were sleeping almost twelve hours in twenty-four, because there was no electricity, no kerosene, no light or anything. Even now in Indian villages, that is the case.
     Thousands of villages have no light, so the sunset is the end of the day. Then what to do? You gossip a little or sing a little, or dance a little and then go to sleep. By the time it is eight, the whole village is fast asleep – and there is no point in getting up too early. So people have been sleeping deeply.
     When a person has slept absolutely, then even if relaxation happens, sleep will not come, because the need for sleep is fulfilled. Relaxation is a step towards both sleep and samadhi. After relaxation there is a bifurcation. Either you go into sleep or you go into samadhi; these are the two possibilities.
     It is very difficult for the modern mind to feel relaxed in the first place. But if you feel relaxed, the second problem is not to fall asleep. People are not sleeping as much as they should, as much as the body needs biologically, and they are not working hard either. Without hard work, sleep is impossible. You have to do hard work, then the body creates the need to relax.
     People are not working and they are not sleeping well, so whenever they start meditating – any meditation like a Buddhist meditation – they start falling asleep. Hence my insistence on active and dynamic methods.
     Once you start tasting...once that opening has started functioning and a few glimpses of satori have come to you through active methods – then you can again start Buddhist methods, and they will be tremendously meaningful.

Osho The Passion for the Impossible

Preparation for Witnessing
     [In the past] a method like Vipassana – which is a Buddhist method – was possible for meditation: just watching the mind silently and meditation happens.
     Meditation was not something arduous or difficult, but to the Western mind or even to the Eastern mind today – which is absolutely overtaken by the Western ideology – watching the mind is not an easy job. So much garbage and so much crap has been forced into the mind that you go almost crazy just watching it. It is a film that begins but never ends. You can go on watching day in, day out, year in, year out and the mind is always ready to supply new images, new dreams.
     It is because of this I had to create a few other devices – Dynamic, Kundalini, and others – before you could enter into a silent witnessing meditation like Vipassana. I have made devices to help you cathart, throw out your garbage rather than waste time in watching it.
     These devices are needed just to clear the rubbish that Christianity has created, and to bring you to a state of naturalness, simplicity ... And from there the only way is witnessing, which is called, by Buddha, Vipassana.

     If you want to do Vipassana, or any silent meditation, Osho Dynamic Meditation becomes absolutely essential, because Christianity having poisoned your mind, that poison has to be thrown out. You have to go completely crazy to throw it out; otherwise that craziness remains inside you, and won't allow you to get into a silent, watching, witnessing meditation.
     So do some Osho Dynamic Meditation, do some jogging, do some running, swimming and when you feel utterly tired, when you feel an intrinsic need to relax, you are free from Christianity. Then you can sit silently, then you can watch your mind – and it is not much. You have thrown out almost ninety-nine percent of it. Maybe here and there a few pieces are clinging because they are very old and have become glued to you ... Just watch them.
     Watching is a process of ungluing those small pieces hanging here and there in the mind. Once they also disappear, you don't have a mind; you have a vast sky opening. That is the explosion, and that explosion will bring you to satchidanand, to truth, to consciousness, to bliss.

Osho Sat Chid Anand

For more from Osho about Vipassana ...New Methods for New Minds