The Hulk needed 576 kilograms of new tissue in four seconds. Wolverine needed to beat the cell cycle by five orders of magnitude. Both questions were jokes with arithmetic attached.
Batman is different, and that’s what makes this the interesting one.
He has no powers. That’s the entire premise of the character — he is a human being with excellent training, excellent equipment and effectively unlimited money. Everything he does is supposed to sit inside the range of human biology. Which means for the first time in this series, the question “what would he take?” has a real answer instead of a punchline.
The real answer is more interesting than the punchline, and considerably more annoying.
Everything below is a research compound. None is approved for the uses discussed here, two are banned in sport, and there are no doses or protocols in this article. This is a thought experiment about a fictional character. Act accordingly.
What a night actually costs
Take the usual figures: 6'2", around 210 pounds, extremely well conditioned.
A night on patrol is maybe four to six hours of climbing, sprinting, grappling and fighting — sustained high-intensity work with brief recoveries. At that intensity a large, trained athlete burns somewhere around 700–1,000 kcal an hour. Call it five hours at 800.
That’s about 4,000 kcal on the night, on top of a resting requirement near 2,000. So roughly 6,000 kcal a day, every day.
Here’s the thing: that number isn’t science fiction. Tour de France riders eat 6,000 to 8,000 kcal a day for three weeks and finish standing up. Batman’s energy demand is demanding, not impossible. It has been met, repeatedly, by actual humans on actual bicycles.
The difference between Batman and a Tour rider isn’t the workload.
A Tour de France rider sleeps nine hours a night, has a nutritionist, a physiotherapist and a team doctor, and gets an off-season. Batman sleeps four hours, eats whatever Alfred left out, and has never had an off-season in eighty-five years.
The actual limiting factor
Batman is nocturnal by design. He works nights and is Bruce Wayne during the day, which means chronic, structural sleep restriction — not an occasional bad night but a permanent deficit built into the job description.
Sleep is where the body does its repair work. Growth hormone releases in pulses during slow-wave sleep. Muscle protein synthesis, memory consolidation, immune function and glycogen replenishment all run on it. Elite athletes are generally advised to get eight to ten hours, and they’re advised that because the performance literature is unusually consistent on the point.
Sleep-restricted athletes show slower reaction times, worse decision-making, reduced time to exhaustion and measurably higher injury rates — one well-known study of young athletes found those sleeping under eight hours were injured substantially more often than those who slept more.
Reaction time and decision-making. For a man whose job is fighting armed criminals in the dark.
Roughly four hours against the eight to ten recommended for athletes under heavy training load. This is the only number in this article that is both real and fixable, and nothing below fixes it.
Hold that thought, because every compound that follows is being asked to solve a problem that is fundamentally a sleep problem.
MOTS-c
If anything in the catalogue were built for this, it would be MOTS-c, and it is genuinely one of the most interesting molecules in modern biology.
It’s a short peptide — sixteen amino acids — and the remarkable part is where it’s encoded. Not in nuclear DNA, like essentially everything else. In mitochondrial DNA. Your mitochondria, the bacterial descendants living inside your cells, are sending signalling molecules out into the rest of the body. Nobody expected that, and its discovery opened a genuinely new category.
What it appears to do is regulate metabolic homeostasis — improving insulin sensitivity and how cells handle energetic stress. In mice it improves physical performance, including in aged animals, which is why it gets called an exercise mimetic online.
Two things that phrase leaves out.
MOTS-c rises when you exercise. It is part of how exercise works, measured in human plasma after training. Which is interesting, and is not the same as evidence that injecting it reproduces the benefit. Adrenaline rises when you sprint; injecting adrenaline doesn’t make you a sprinter.
There are no human performance trials. Not weak ones. None. The mouse data is real and it's promising and it has not been carried across.
Striking rodent results, a genuinely novel mechanism, and nothing yet showing it does anything measurable for a person’s endurance.
Verdict for Batman: the most scientifically interesting thing on the list, and the least able to tell you what it would do to him.
Retatrutide would make Batman worse at his job
This one needs stating plainly, because retatrutide is the most genuinely effective compound in this entire article and it is also completely wrong for the stated purpose.
Retatrutide is a triple agonist — it hits the GLP-1, GIP and glucagon receptors at once. The phase 2 results were extraordinary: participants on the highest dose lost roughly 24% of their body weight over 48 weeks. That is a remarkable result and the phase 3 programme is running now. It is not approved.
It is a weight-loss drug. It is not an energy drug.
The confusion comes from the glucagon arm. Glucagon receptor agonism does raise energy expenditure — which sounds like “more energy” and means the opposite. Raising energy expenditure means your body burns more fuel at rest. That is excellent if your goal is losing fat. It is not excellent if your goal is having more available output for a five-hour shift, and it's actively unhelpful if you're already running a 6,000-calorie deficit-adjacent day.
Then the part that actually matters for a fighter.
When people lose weight on GLP-1-class drugs, a substantial share of what they lose is lean tissue, not fat — commonly estimated somewhere between a quarter and 40% of total weight lost. That’s a known and much-discussed property of the class, and it’s why resistance training and protein intake are pushed so hard alongside them.
Batman does not have a body-fat problem. Putting him on a triple agonist takes mass off a man whose job requires him to be heavier and stronger than the person he’s grappling.
Fine, and manageable, if the goal is fat loss. A direct subtraction from performance if the goal is grappling with armed men on rooftops.
Verdict for Batman: the drug here with the strongest human evidence behind it, aimed at a problem he doesn’t have, with a side effect that is precisely the thing he can’t afford.
BPC-157 and TB-500
We took these apart in detail in the Wolverine piece — the short version is that BPC-157 has a large rodent literature traceable largely to one research group, no published human randomized trials for tendon healing, and a parent protein nobody has ever isolated; and that TB-500 is a short fragment while essentially all the research people cite is on thymosin beta-4, the full 43-residue protein. Both have been banned in sport since 2022.
What’s worth adding here is the specifically Batman-shaped problem, which isn’t about either compound.
His injury pattern is chronic repetitive trauma without adequate recovery time. Tendons and ligaments are poorly vascularised; they heal slowly because they get less blood than muscle does, and there is no signalling molecule that changes their blood supply on a useful timescale. Load a partially-healed tendon repeatedly and you don’t get a slower recovery, you get a different condition — chronic tendinopathy, a degenerative change in the tissue rather than an injury that's mending.
The thing that prevents that is time under reduced load. Batman's entire character forecloses it. He goes out the next night because that's who he is, and no amount of anything in a vial substitutes for the week he won't take off.
What would actually work
Here’s the irritating part. The interventions that would measurably improve Batman’s performance are all extremely boring and all extremely well evidenced:
Sleep. Moving from four hours to seven would do more for his reaction time, decision-making, injury rate and recovery than every compound in this article combined, and the evidence base for that claim is enormous compared to the evidence base for anything else here.
Eating enough. 6,000 kcal a day with adequate protein, structured around the work. This is literally what Tour de France teams do, and it's why they finish.
Periodisation. Planned lighter weeks. Every elite athletic program on earth builds them in because training without recovery stops producing adaptation and starts producing injury.
Actual physiotherapy. Progressive loading protocols for tendon injuries have real human trial evidence behind them — the kind BPC-157 doesn't have.
A support team. Batman already has the best version of this available: a full-time person managing his logistics, nutrition and medical care. Alfred is, in performance terms, the single most evidence-based intervention in the entire Batman apparatus.
So which peptides does Batman take?
For energy: none of these would help, and one of them would hurt.
MOTS-c is the most interesting molecule here and has never been tested in a human for performance. Retatrutide works better than anything else on the list and is solving a problem Batman doesn't have, while removing mass he needs. BPC-157 and TB-500 are aimed at a recovery problem whose actual cause is that he won't stop.
And this is the piece where that conclusion carries real weight, because Batman is the one character here who could plausibly use any of it. The Hulk was blocked by thermodynamics. Wolverine was blocked by the cell cycle. Those are hard walls and no drug was ever getting past them.
Batman isn’t blocked by physics. He's a human being with a workload elite athletes genuinely survive. Everything about his problem is tractable.
And the answer is still sleep, food and rest — the three things with the largest evidence bases in all of sports science, and the three things no vial has ever replaced.
The only character on this list who could actually benefit from a peptide is the one who needs a nap instead.
That’s the pattern underneath every piece on this site. The compounds with the most exciting stories have the least evidence. The interventions with overwhelming evidence are boring, unglamorous, and free.
Nobody is selling sleep.