A first distinction matters here. This question is usually about ordinary, persistent tiredness, the kind that builds from poor sleep, ongoing stress, or a demanding stretch of life. It is not about myalgic encephalomyelitis, the disabling illness sometimes labeled chronic fatigue syndrome, which is a separate medical condition with its own course. The everyday version is what most people mean when they say they feel drained, and it is the version this answer addresses.
That answer comes with a caution attached. Tiredness that lasts more than a couple of weeks, or that arrives without an obvious reason, can be a signal rather than a mood. Anemia, an underactive thyroid, low iron or vitamin B12, sleep apnea, and depression all show up first as fatigue. Mayo Clinic advises seeing a doctor when fatigue is unexplained or persistent, because a blood test or exam may find a cause that no relaxation technique can touch. The honest starting point is medical, not mental.
Where hypnosis fits is narrower and more modest. Once a physical cause has been ruled out, a portion of everyday low energy is tied to how the mind runs through the day: tension that never quite releases, a racing head at night that wrecks sleep, worry that quietly burns through reserves. A relaxation-based hypnotherapy session works on that layer. It guides a person into a calm, focused state and uses suggestion and imagery to lower arousal, which some people find helps them wind down and sleep more soundly.
The link to energy is indirect, and worth stating plainly. Hypnosis does not add fuel to the body or correct a deficiency. What it may do, for some people, is reduce the stress and poor sleep that drain energy in the first place. Better rest and lower tension can leave more of the day’s capacity intact. That is a real effect for the right person, and a limited one.
It also sits alongside the basics rather than above them. Steady sleep, movement, food, and reduced strain do most of the heavy lifting for low energy, and hypnosis is at most a support to those, not a substitute. Anyone whose exhaustion is severe, lasting, or paired with other symptoms is better served by a medical workup than by a session aimed at relaxation. Kept in that frame, the technique offers something quiet rather than dramatic: a calmer nervous system, and the rest that can follow from it.