Humans are indeed made of material that originated in stars, though the phrasing “stardust” is a convenient shorthand. Most of the elements that compose the human body were formed in stars and stellar explosions long before Earth existed, and only a small portion of our mass (hydrogen) traces back to the very early universe. Here’s a concise breakdown of what that means. What this means in practice

• Most common elements in the body: About 65% oxygen, 18% carbon, 10% hydrogen, 3% nitrogen, with smaller amounts of calcium, phosphorus, and others. These elements were forged in stars or during stellar events, not created on Earth. This reflects that our atoms were assembled in previous generations of stars and distributed by supernovae and stellar winds long before the Solar System formed. [source-derived context from scientific summaries of stellar nucleosynthesis]
• How those elements got here: Hydrogen and helium were produced shortly after the Big Bang. Heavier elements (everything else in the body) were synthesized inside stars through nuclear fusion and dispersed via supernovae and other stellar processes. Over billions of years, these “star-made” atoms became part of gas clouds that formed new stars, planets, and eventually life, including humans. [general cosmology and nucleosynthesis understanding]
• The “star stuff” nuance: The phrase is technically accurate for most elements that constitute the body, though the most abundant element, hydrogen, has origins tied to the early universe rather than stellar interiors. The remaining mass is built from elements created in stars and stellar explosions. [widely cited explanations of elemental origins]

A few commonly cited takeaways

• We carry atoms that date back to ancient stars: Many carbon, nitrogen, oxygen, and other atoms in the body have ages on the order of billions of years, having been built in prior generations of stars. [astronomy education resources]
• We contain “special” stellar leftovers: Heavier elements like iron, calcium, and phosphorus come from advanced stellar processes and supernovae, and even some trace elements (including tiny amounts of gold) are products of extreme stellar events. [astronomy and astrophysics explanations]
• The overall idea remains powerful: The connection between humans and the cosmos is direct—the same fundamental building blocks that made up ancient stars are now part of living organisms here on Earth. [popular science summaries]

If you’d like, I can tailor this into a short, kid-friendly explanation, a classroom-ready slide, or a concise answer suitable for a science FAQ.