A Utah Company Says It Made Human Sperm in a Lab. Here's What That Means

Paterna Biosciences, a startup in Salt Lake City, says it has grown human sperm in the laboratory from cells found in testicular tissue. The company reports that it has also used this lab-grown sperm to create embryos, as a test to see if the approach works. These claims have been reported by Wired, but independent scientists have not yet reviewed or verified the results.

The company's method takes stem cells from testicular biopsies—small tissue samples taken from the testicles—and grows them into mature sperm entirely outside the body. Co-founder and CEO Dr. Alexander Pastuszak, a urologist who specializes in male reproductive health, says the lab-grown sperm appear to work the same way as sperm made naturally, based on early tests.

How the Technology Works

Paterna's approach targets a problem scientists have struggled with for nearly a century: making sperm in the lab. The company focuses on stem cells that already exist in the testicles, rather than trying to reprogram other cells into sperm-producing cells—a method some other research groups are exploring.

The company reports it has successfully grown sperm from dozens of tissue samples and says a single biopsy can generate thousands of sperm. The lab-grown sperm go through all the biological steps needed to fertilize an egg. The company created embryos to prove the concept works, not with any intention of implanting them or creating pregnancies.

Worth flagging: While this is a notable claimed milestone, the company's results have not been independently verified by other scientists. Major questions remain about whether the results can be repeated reliably, whether the approach is safe, and whether it actually works in patients.

What This Could Do for Patients

The technology could help men who cannot produce sperm naturally—either because of medical conditions, infertility, or as a side effect of cancer treatment. Around one in six couples struggle with infertility, and male factors account for roughly half of those cases. Currently, there are no FDA-approved medicines designed specifically to treat male infertility.

The approach could be particularly valuable for men with non-obstructive azoospermia, a condition in which the body makes little or no sperm but still has the stem cells needed to create it. It could also benefit young boys undergoing chemotherapy, since sperm-forming stem cells are present from birth and could theoretically be preserved and used later in life.

The Business Side

Paterna raised $6.4 million in seed funding in October 2024, following an earlier $6 million investment round. The company estimates the eventual treatment will cost between $5,000 and $12,000, similar to other fertility treatments that already exist.

The company plans to conduct larger clinical studies with infertile men, then move toward a major trial using the lab-grown sperm in standard fertility procedures. Paterna has won recognition from the Mayo Clinic and Arizona State University's health technology program, including a Disruption Award in March 2025.

The Scientific Team

Paterna brought on Dr. Kyle Orwig, a reproductive biology researcher, as co-founder in January 2024. The company also works with Bradley Cairns, a University of Utah professor who studies the biology of sperm. The team has published research showing that men with infertility have higher rates of genetic mutations in their sperm compared to men who can reproduce naturally.

This finding supports the company's broader argument: male infertility has received far less scientific attention and fewer treatment options than female infertility, where technologies like IVF (in vitro fertilization) have become well-established.

Major Obstacles Ahead

Analysis: We have seen this pattern before. When IVF was first developed in the 1970s, it was meant to help women with blocked fallopian tubes. Today, it is used for dozens of different reasons and has produced over 500,000 births annually. Reproductive technologies often start narrow and expand over time—but they must first prove they are safe and effective.

For lab-grown sperm to become a real treatment, the company must clear substantial hurdles. Creating sperm in the lab involves intricate biological processes—organizing DNA, dividing cells correctly, and ensuring the final product is fully functional. Even small mistakes can lead to genetic errors or damaged sperm, and these problems might not be obvious at first glance.

Regulators have no established pathway for approving lab-made gametes, which means Paterna will need to conduct extensive safety studies. Scientists will also need to track the health of any children born from this approach, possibly for years or decades, to ensure no long-term problems emerge.

Worth flagging: The fact that the company created embryos for this experiment raises ethical questions about research using human embryos, which different countries and states approach very differently.

What Comes Next

In this author's view, if Paterna's results hold up under scrutiny, the technology could genuinely help men with severe infertility—a medical need that has long been underserved. It might eliminate the need for surgical procedures to retrieve sperm in some cases and open new options for men who currently have few choices.

But a large gap remains between a laboratory result and a treatment that doctors can actually offer to patients. The company's embryo creation is encouraging as proof-of-concept, but it is not proof that the approach is safe or effective in real patients. Independent scientists need to verify the company's work, and then extensive testing must follow before this reaches clinical use.

Beyond individual patients, success here could change how fertility preservation works for young people facing cancer treatment or other conditions that affect reproduction. That is a meaningful potential impact—but it depends on what happens next.