Miracles and discernment · Question 12
Are all those Eucharistic miracle photos and stories certified by the Vatican?

The question: “Can I trust the videos that say they checked heart tissue and even the blood type under a microscope?”
The Church's answer: Being on a list online doesn't make a case officially recognized. A claim involving the Eucharist also has to be investigated by the diocese with jurisdiction — the facts, the chain of custody, the possibility that the sample was contaminated, the testing laboratory, and the original text of the report — and the Dicastery for the Doctrine of the Faith is involved where necessary. A photograph alone can't establish where a specimen came from, and anonymous scientists, tests that never name a published paper, and articles copied from one another can't verify anything. Nor should anyone talk as though the Holy See maintains a single complete “authorized list of Eucharistic miracles.”
What the Church has actually recognized: A diocese's decision to permit veneration or devotion, a judgment dealing with the supernatural character of an event, and an individual test report have to be kept distinct from one another. Eucharistic faith doesn't hang on one viral photograph.
An analogy — check the label on the sample first
Even if a jar in the science lab has “meteorite dust” written on it by hand, the findings are hard to trust without a record of where it came from and how it was kept. With a claimed Eucharistic miracle too, who tested what sample, where, and by what method comes first.
If they press further: “So are all Eucharistic miracles fake?” — There's no basis for concluding that all at once either. Check the official diocesan document and the original test report case by case, and where the documentation is missing, the honest thing is to suspend judgment.
In one sentence: “A Eucharistic miracle video isn't Vatican certification. The diocesan document, the origin of the sample, and the original test report have to be checked separately for each case.”