Written by the Spacemilk team · Last updated October 2026

A serving of Spacemilk yeast protein contains about 38mg of purines, which is low next to many everyday protein foods: a 3.5 oz (100g) portion of chicken breast has about 141mg. The concern about yeast and purines is real for whole yeast, which is very high in purines, but yeast protein isolate is a different product, and our process includes a step that reduces the yeast's nucleic acids, the source of its purines. If you have gout or are managing uric acid for a health reason, talk to your doctor before adding any new protein.

Why do people ask whether yeast protein causes gout?

Because whole yeast is one of the richest sources of purines you can eat. Yeast cells grow fast and are packed with nucleic acids, especially RNA. In yeast biomass, nucleic acids typically make up 5–8% of the cells (Jach et al., 2022, Metabolites). The body breaks the purines in those nucleic acids (adenine and guanine) down into uric acid, which is why researchers note that single-cell protein made for people needs its nucleic acid content reduced (Jach et al., 2022).

You can see how high whole yeast runs in published measurements. In a study that measured purines in 270 foods, a brewer's (beer) yeast supplement measured about 2,996mg of purines per 100g, among the highest of anything tested (Kaneko et al., 2014, Biological and Pharmaceutical Bulletin).

So when blogs and short videos warn that "yeast protein is high in purines," they're usually reasoning from whole yeast. Spacemilk is not whole yeast. It's protein isolated from non-GMO baker's yeast, with the rest of the yeast separated out and no live or active yeast left in the bag.

How many purines are in yeast protein?

Spacemilk contains about 38mg of purines per serving, made up of roughly 22mg of adenine and 16mg of guanine. Each serving delivers 20g of complete protein. Our process includes a step that reduces the yeast's nucleic acids (where its purines come from), which is a big part of how an isolate ends up so far from whole yeast.

One honest note on units: purine tables usually list milligrams per 100g of food. A serving of Spacemilk is only about 25 to 29g of powder, depending on the flavor, so measured per 100g of powder the number would be higher than 38mg. The fair comparison is by what you actually eat in a sitting, which is how the table below is set up.

How does that compare with common foods?

Food	Amount	Total purines
Spacemilk yeast protein	1 serving (20g protein)	about 38mg
Chicken egg	100g	0mg (not detected)
Milk	100g	0mg (not detected)
Firm tofu	100g	31mg
Beef (shoulder sirloin)	100g	90mg
Pork (sirloin)	100g	91mg
Salmon	100g	119mg
Chicken breast	100g	141mg
Tuna	100g	157mg
Sardine	100g	210mg
Beef liver	100g	220mg
Chicken liver	100g	312mg
Brewer's yeast supplement	100g	2,996mg

Food values are total purines as measured by Kaneko et al., 2014, rounded to the nearest milligram. Spacemilk's figure is per serving from our own product data.

Two things stand out. First, a serving of Spacemilk sits well below a typical portion of chicken, fish or red meat, and far below organ meats and whole yeast. Second, eggs and dairy measured essentially no purines, so they come in lower than Spacemilk. We'd rather you see the whole picture.

Does yeast protein raise uric acid?

Spacemilk itself hasn't been studied for its effect on uric acid levels, so we won't claim it has none. What we can tell you is the composition: about 38mg of purines per serving, with a manufacturing step that reduces the yeast's nucleic acids. For context, the authors of that food study note that Japanese recommendations call for keeping dietary purines under 400mg a day (Kaneko et al., 2014). Purines are only one part of the picture, and current gout guidance from the American College of Rheumatology covers medication and lifestyle together (FitzGerald et al., 2020, Arthritis Care & Research). Your doctor can tell you what applies to you.

Is all yeast protein the same on purines?

Not necessarily. Purine content depends on how the protein is made and how much of the yeast's nucleic acid is removed along the way. Nutritional yeast and brewer's yeast are whole, deactivated yeast, not protein isolates, and they're a different story entirely. If you're comparing products, look for a stated purine figure per serving rather than assuming.

Every batch of Spacemilk is independently third-party tested for heavy metals, microbials, pesticides and allergens, and every result is published on our testing page. You can read more about how yeast protein is made and studied on our Science page.

Who it's for, and who should check with a doctor

This page is for you if you're curious about yeast protein, you've seen the purine warnings online, or you're keeping an eye on purines in your diet and want the actual number.

Talk to your doctor first if you have gout, high uric acid or kidney stones, take medication to manage uric acid, or have been told to follow a low-purine diet. This page shares composition facts, not medical advice.

Frequently asked questions

Is yeast protein high in purines?

Whole yeast is. Spacemilk, a protein isolated from baker's yeast, has about 38mg of purines per serving, and our process includes a step that reduces the yeast's nucleic acids, the source of its purines.

Can I have yeast protein if I have gout?

That's a question for your doctor, who knows your history and medication, but here's what to bring them. Whole yeast is high in purines because it's packed with nucleic acids. Spacemilk isn't whole yeast: it's the protein isolated from baker's yeast, and our process includes a step that reduces those nucleic acids. The result is about 38mg of purines per 20g-protein serving, less than a typical portion of chicken (about 141mg per 100g), salmon (about 119mg) or beef (about 90mg). Eggs and milk measure lower still. Share those figures with your doctor and decide together.

Is yeast protein lower in purines than meat?

Per serving, yes. One serving of Spacemilk has about 38mg of purines, compared with about 141mg in 100g of chicken breast and 119mg in 100g of salmon (Kaneko et al., 2014). Eggs and milk measured lower than Spacemilk.

Is Spacemilk the same as nutritional yeast or brewer's yeast?

No. Those are whole, deactivated yeast. Spacemilk is the protein isolated from baker's yeast, with no live or active yeast in it.

Where can I learn more?

See how yeast protein compares on protein quality in Yeast protein vs whey, read about allergies and candida in Can you have yeast protein with a yeast allergy or candida?, browse our FAQ, or shop Spacemilk Complete Protein.