Is Botox haram for men?

It depends on the reason. Botox used as medical treatment, for example for migraines, heavy sweating or muscle spasms, is allowed. Botox or fillers just to smooth wrinkles are disputed: some scholars allow them as temporary and safe, others forbid them as altering creation and hiding age. If you're unsure, leaning toward caution is reasonable.

Medical use is treatment

Doctors use botulinum toxin (Botox) for conditions like chronic migraines, excessive sweating, eye twitching, jaw clenching and muscle stiffness. This falls under treatment, which Islam encourages. The Prophet ﷺ said, "Make use of medical treatment, for Allah has not made a disease without appointing a remedy for it" (Sunan Abi Dawud 3855). If a qualified doctor recommends it for health, there's no issue.

Cosmetic Botox and fillers: two views

The disagreement is about wrinkles and lines that come from ageing. Here is how the two sides reason.

Those who allow it: it's temporary and wears off, it doesn't remove or permanently reshape anything, and smoothing lines for confidence is not the same as changing someone's features. They require that it's safe, done by a qualified person, and not used to deceive anyone.
Those who forbid it: they see it as changing the natural form for beauty alone, add the health risks, and say it resists the natural process of ageing. Some also point to wasted money.

Both views exist among serious scholars, so this isn't a simple halal or haram. The wider principle of changing Allah's creation is explained here. See Is plastic surgery haram?

Ageing is not a flaw to be hidden

The Prophet ﷺ spoke of old age as the one thing that medicine doesn't cure (Sunan Abi Dawud 3855). He also forbade plucking out grey hair and called it the Muslim's light (Jami at-Tirmidhi 2821). Lines and grey hair show years lived, and Islam gives them dignity. Many men find it easier to accept ageing with this in mind.

That doesn't make skincare wrong. A man who looks after his skin, sleeps well and wears sunscreen is doing nothing wrong. See Is skincare haram for Muslim men?

Questions to ask yourself

Why do I want it? If it's for a medical issue or a real health reason, that is different from chasing youth or the approval of others.
Is it safe? Use a licensed clinician. Cheap or unregulated injections can cause drooping, bruising or worse.
Is it a wise use of money? Botox lasts months, so it's a repeat cost, and Islam asks us to avoid waste.
What's in it? Ask what the product is made from if you want to avoid animal-derived ingredients.

A calm way to decide

If your reason is purely medical, go ahead. If it's cosmetic, give it a few weeks, pray istikhara if you like, and ask a trusted local scholar who knows your situation. Don't let anyone shame you either way.

Key points

Medical Botox is treatment and is allowed.
Cosmetic Botox and fillers are disputed among scholars.
Safety, honesty and need all matter.
Islam gives dignity to ageing; grey hair is called a light.

Tip: If you only want to look rested, try the basics first: sleep, water, sunscreen and a good moisturiser. They cost little and raise no questions.