Most capsules either contain powdered, dry herbs, or a tiny bit of liquid extract (gel caps). Tablets are powdered herbs that are held together by pressure and other chemicals. The beauty of liquid extracts, or "tinctures," is that they absorb quickly and the body receives the full benefit of the plant in a very bio-available solution. Liquids also allow you to customize your serving freely so you can best meet your needs at the time. Liquids are inexpensive and easy to swallow. The droppers and pump top dispensers are also convenient for when you're on the go.
The effects are strongest while you are listening to the tones because your brainwaves are synchronized and tuned into the frequency range you desire at that time.  After you've stopped listening the effects can still linger for a while afterwards.  The timescale will vary from person to person and be affected by what you do after you've stopped listening.
2. The other thing you cannot afford to do is evaluate whether or not a technique is having an effect based upon having (or not having) any of those superficial, irrelevant, distracting phenomena discussed above, like face flushing, seeing light swirls, having sensations of this, that or the other thing, etc. Those kinds of phenomena will just lead you down the wrong path and steer you away from the true benefits of meditation. If you’ve already fallen into the trap of this sort of conditioning, using something like the Release Technique, the Sedona Method, or even EFT can be helpful in breaking established conditioned associations.
After you fully understand the above principles, the next source of poor results to consider arises from faulty expectations and misunderstandings about what meditation and brainwave entrainment are, and what the experience of either one of them is like. Meditation and Brainwave entrainment aren’t synonyms but the misunderstandings about them do have some overlapping areas. Some misunderstandings are common to both while some are unique to one or the other.
Generally speaking, the brain will usually entrain to the strongest stimulus which would be isochronic tones over binaural beats. So when you see people add binaural beats at a different frequency to the isochronic tones, that would not produce additional brainwave entrainment at another frequency. If they are both at the same frequency I haven’t seen any research to indicate whether that would be beneficial or not, but my belief is that it would weaken the potential for entrainment. When you look at the waveform of an isochronic tone there is a distinct empty space between each beat, making it very pronounced and effective. When you add binaural beats at the same frequency it looks like this: The depth of the waveform is now half as deep and less effective. This is before the binaural beats are formed inside your head, where the waveform is hard to determine and measure. From listening to that type of combination the beats sound much less pronounced, which has to make them much less effective in terms of a brainwave entrainment stimulus, compared to isochronic tones on their own.
We may use the term “to meditate” as a convenience, but always keep in mind, what is really meant is that we enter into a state of meditation. It’s an important point to distinguish because if we get caught in the trap of regarding meditation “as a verb” it leads into all sorts of problems and misunderstandings. If a person incorrectly believes meditation is a verb, they generally also confuse whatever technique they use to arrive at a state of meditation as being meditation in and of itself.

Both brainwave entrainment and neurofeedback deal with brainwaves, but the similarity stops there. Entrainment pushes your whole brain into a pre-determined state, while neurofeedback teaches you how to move specific parts of your brain on your own. It is the differeence between forcing the brain into a given position, and skills building so you can move it there yourself.