Issac Thorne

Last Updated January 9, 2022

How Long for Phenibut to Kick in?

Wondering how long it takes for phenibut to kick in?

The onset of phenibut is quite subtle. For this reason, people new to phenibut often experience a bit of confusion with regard to how long phenibut takes to work.

Anyone who has introduced the supplement to a first-time phenibut user has likely experienced this; new users are usually “unsure” of whether or not it is working, or claim they can’t feel it at first.

There are likely two reasons for this:

  1. New users are expecting more of the “immediate punch” that harder drugs pack.
  2. The phenibut high comes on as a slow, controlled climb that is difficult to track.

Rest assured; it is working.

Phenibut takes about 2 hours to kick in for most people.

It will also have kicked in after about 2 hours for new users, but they may be less familiar with the effects and not recognize it as early.

Phenibut peaks in about 4-6 hours, with a half-life of about 5.3 hours.

How long phenibut lasts from here will vary depending on your phenibut dosage. You should come down pretty quickly after the 6-hour mark or so. In higher doses, however, you may still feel the milder effects for over 20 hours.

How to Make Phenibut Work Faster

Because it can take a while to kick in, many users wonder if there is a way to make phenibut work faster.

The general consensus amongst phenibut users is that it is more effective to take phenibut on an empty stomach. Some people claim that they cannot feel the effects of phenibut if they take it on a full stomach.

Most absorption of drugs takes place in the small intestine, due to it having a greater surface area and permeability than the stomach. Phenibut is no different, and is also absorbed mostly by the small intestine when ingested.

Food must be processed by the stomach before reaching the small intestine. For this reason, taking phenibut on a full stomach will delay the process of getting it through to the small intestine where it is absorbed.

Because of this, phenibut will kick in faster when it’s taken on an empty stomach.

Although, if this causes stomach sensitivity for you, you may prefer to take it with a small meal.

Does Phenibut FAA Work Faster?

Phenibut FAA differs from Phenibut HCl in several ways.

Primarily, phenibut FAA has a more neutral pH level than phenibut HCl, so it can be taken sublingually.

For those who do not wish to take phenibut on an empty stomach, but still want it to kick in quickly, this may be a decent option.

Taken sublingually, you may find that phenibut FAA kicks in faster for you.

Keep in mind, however, that phenibut FAA is more expensive and less common than phenibut HCl.

If the sublingual method does not appeal to you, I recommend phenibut HCl over phenibut FAA.

To make phenibut work faster, you might prefer to take it on an empty stomach. Taking it sublingually in its free amino acid (FAA) form may also speed up the process.


Phenibut typically takes about 2 hours to kick in. Experienced users may recognize the effects earlier, while new users may take longer to notice the effects.

The phenibut peak occurs about 4-6 hours after taking it, with the half-life being about 5.3 hours.

After about 6 hours or so without redosing, the effects will quickly start to diminish.


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