In the early 1990s, amid the bloody war tearing apart the former Yugoslavia, a team of researchers in Croatia working across biochemistry, pharmacology and medicine, published their discovery of a peptide that seemed to have amazing healing properties. They unofficially called the peptide the ‘God help substance’ in a nod both to its apparently spectacular properties and to the war raging around them.
Their work on the peptide, which they isolated from human gastric juice and officially named body protection compound (BPC-157), continued quietly in the ensuing decades, leading to over 150 papers and 100 PhDs. A hypothesis related to the concept of ‘cytoprotection’ followed, suggesting how the peptide works by protecting blood vessels and, therefore, organs during stress, counteracting everything from tissue damage to brain diseases and even tumours in animal models.
However, several experts Chemistry World spoke to questioned these health claims, especially given that the peptide has not passed any significant openly-available human clinical trials, and said that its effectiveness or lack of in humans remains to be proven. The peptide did undergo small, early-stage human trials for ulcerative colitis in early 2000s by pharma company Pliva. However, these results were never fully published and the compound never progressed to a phase 3 trial. Human trials of BPC-157 are ‘very limited’ and ‘suffer from small sample sizes, lack of appropriate and broad-ranging controls, and insufficient randomization’, according to a March 2026 paper that reviewed human data on BPC-157.
Some researchers even question whether the peptide has been correctly isolated, and whether it is actually produced by the body given the evidence for the gene that encodes it and receptors that interact with it are still scarce.
Now, in an unlikely twist, US politics has catapulted the team into the international spotlight. ‘BPC-157 is having a moment,’ claimed a recent Undark/STAT News article, which described it as a ‘buzzy peptide’ that is ‘hyped as a cure-all’ while being embraced by influential podcasters, wellness clinics and people seeking various health benefits as they procure it from unregulated online sources.
Media interest doesn’t match up with safety
‘We were expecting something like that, so this is not a surprise,’ says Predrag Sikirić, an emeritus professor at the University of Zagreb, talking about the media storm engulfing his research. ‘You have a concept, you have data, you have findings, therefore, altogether this means that it has to be acknowledged by the public at some point.’
The sudden media interest follows a Food and Drug Administration (FDA) statement in April that it would hold a meeting this summer to consider easing restrictions on peptide therapies. The FDA move, in turn, follows pledges to loosen regulation by the US health secretary Robert F Kennedy Jr, who told a podcast in February he was ‘a big fan of peptides’. Such peptides are also reportedly popular among some prominent supporters of his Make America Healthy Again (MAHA) movement.
BPC-157 is one of seven peptides on the FDA’s list of unapproved, high-risk compounds to be reviewed, although it is already being sold online as a health supplement.
‘Naturally, I’m interested in a positive outcome, because I am very, very, very confident that this would be, let’s say, helpful for mankind,’ says Sikirić, who claims his team’s data, the Pliva trials, which he says were positive, and independent studies, show the compound is safe and effective for a range of health issues.
However, other medical professionals and scientists note it has not been through enough human clinical trials, raising safety concerns. In 2023, the FDA cited the ‘potential significant safety risks’ of consuming such peptides, specifically immunogenicity risks for BPC-157, and little if any information to evaluate if it’s safe for humans.
An FDA spokesperson told Chemistry World its upcoming meeting will ‘discuss and consider the risks and safety information associated with peptides’.
Media reports have also flagged Sikirić’s commercial interest in BPC-157, noting that his patent for a stable version of the compound is for sale. ‘Naturally, everybody is interested in promoting their own findings,’ he says, ‘but the financial interest is not the prime one. We have no bias just because we are involved in a couple of patents.’
Vladimir Trkulja, acting head of the pharmacology department where Sikirić is based, is sceptical of the health benefits of the peptide, given the dearth of human studies. ‘I am not aware of any formal human study in which this peptide was used,’ he tells Chemistry World. ‘I am aware that in the USA and some other countries there is huge hype about this thing, but I do not really understand the basis for it.’
Christopher Robinson, a physician–scientist at the Johns Hopkins University School of Medicine in the US, who is seeking funding to test BPC-157 in human trials, says peptides are ‘a very exciting topic right now’ but that ‘current clinical trials are limited’. He adds that ‘given the limited research, as a scientist, I cannot say that they have proven efficacy, but I am hopeful’.
Flynn McGuire, a chief medical resident at the University of Utah Health, US, said ‘there are valid concerns about the current state of the evidence base. The fact that much of the research has been published by a relatively small number of teams, often in less demanding journals and without sufficient independent replication is definitely concerning.’
‘That said,’ he adds, ‘there have been a few studies published outside of Croatia that report broadly similar findings, which is somewhat reassuring, though still not definitive. In terms of conclusions about human health, without randomised controlled clinical trials in humans, it’s very difficult to draw firm conclusions at all. At the same time, I think there is enough preclinical evidence to justify further, more rigorous investigation.’
Similar views were shared by other researchers Chemistry World approached.
Funding for clinical trials hard to come by
Sikirić maintains that a large part of his studies were published in high-impact factor journals. He adds that around 30 papers showing BPC-157 efficacy were published outside Croatia by independent groups.
Sikirić is adamant that, based on ‘all the details about the effectiveness of BPC-157, and all toxicology data’, the compound’s safety profile is ‘perfect ’. He admits most of the data come from animal studies but adds that ‘animal experiments, if properly done, are more than 100% assurance that everything is working in the human as well’. Sikirić says he is open to new collaborations, and would be ‘more than interested in running a clinical trial’.
But he is yet to see any translation of media interest into more funding or opportunities for expanding his research. ‘More interest equals more funds: if this equation was working, I would be the happiest person,’ he says.
Jelena Šuran, chief executive of Apiotix Technologies that develops bee-derived bioactives, who previously studied BPC-157 with Sikirić, says ‘it’s good to see such interest in BPC-157’. But she doesn’t think it will ‘bring R&D attention and funding to Zagreb’. ‘Besides temporary media interest and a few interesting articles, I don’t think there is much benefit to all this hype,’ she says. ‘MAHA longevity-aspiring investors don’t like to give their money to fund science unless it benefits them directly.’
‘If the FDA lifts the ban, this might only help to increase the revenues of numerous peptide sellers and so-called longevity clinics, but not Sikirić,’ says Šuran. ‘He will continue going to his work every day, in the same old car, doing the same thing as ever – teaching students pharmacology and doing several more experiments with BPC-157, again.’
However, Sikirić says he has bigger plans for further research on BPC-157. He anticipates a ‘big new venture’, in which renewed interest in the peptide could support a broader research initiative to investigate the peptide’s therapeutic and healing potential. ‘In science, you are never all done,’ he says. ‘There is always an area that still has to be investigated.’
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