California’s New Creatine Law: Protecting Teens or Going Too Far?

California will restrict sales of certain muscle-building supplements to minors in 2027. The case for limiting high-caffeine pre-workouts is easier to make than the case for restricting plain creatine or protein powder.

A teenager looking to get stronger can walk into a supplement store and find a tub of creatine, a bag of whey protein, and a pre-workout that promises to get him through his toughest session. All three can be marketed to the same kid. If you’re the parent standing next to him, you have to turn the containers around to understand how different they are.

I understand why California wants to protect kids from risky supplements. I’d be concerned if a teenager were stacking caffeinated products before practice or taking a blend that promised to boost testosterone. I’d have a different conversation about plain creatine or a protein shake. The research gives us good reasons to make those distinctions.

What California’s new supplement law actually does

Starting January 1, 2027, California’s Assembly Bill 2030 restricts retail and delivery sales to people under 18 of over-the-counter diet pills and dietary supplements marketed for weight loss or muscle building. The law includes age-verification provisions and a prescription exception. Read the chaptered bill.

The Barbell Spin framed it as a ban on minors buying creatine. The law looks at how a supplement is labeled, marketed, or otherwise represented. Creatine is one factor courts can consider. Plain creatine marketed for muscle building can fall under the rule. A protein powder sold as a conventional food falls outside the dietary supplement definition, while one sold as a dietary supplement and marketed for muscle building may be covered. The law regulates sales and delivery to minors.

The concern about teenagers is real

A San Diego supplement-store owner told 10News he rarely sees teenagers come in to buy creatine. An eating-disorder therapist interviewed for the same story described hearing from families whose teens had already gotten hold of supplements. She also said she was seeing younger boys struggling with online pressure about how their bodies should look. 10News San Diego coverage.

The store owner sees who walks through his door. The therapist hears from families who have a reason to ask for help. Neither account tells us how often a particular supplement causes harm. Both point to a question parents can ask at home. What are you hoping this will do for you?

A kid who wants more power off the blocks may be asking a sports performance question. A kid who thinks he has to get bigger because everyone on his feed looks bigger may need a different conversation. The same tub can show up in either one.

Caffeinated pre-workout is where I’d draw a harder line

If my teenager brought home a pre-workout, I’d look at how much caffeine was in a serving and ask what else they’d had that day. Coffee before school, an energy drink at lunch, and a scoop before practice can feel like three separate decisions. The caffeine adds up. Too much can cause a racing heart, anxiety, and digestive symptoms. Swallowing the powder dry adds a risk of choking or breathing problems. The NIH also warns that some sports supplements have contained undeclared stimulants, steroids, or other drug ingredients. American Academy of Pediatrics guidance and NIH sports supplement fact sheet.

• A 25-year-old had a heart attack after dry scooping a pre-workout. The clinical report describes what happened after use of a multi-ingredient product. It can’t isolate caffeine as the cause. Published case report.
• A 20-year-old developed chest pain, coughing, and sweating after dry scooping. Poison Control describes a reported heart attack, with caffeine suspected as a contributor. Poison Control case summary.
• A child developed seizure-like activity and serious muscle breakdown after a caffeine overdose. This pediatric report documents caffeine poisoning. The two pre-workout cases above involved adults, and these reports don’t tell us how often teens are harmed by pre-workout. Pediatric emergency medicine case report.

This is where the case for an age restriction makes the most sense to me. A teenager can combine concentrated stimulants without thinking about the total. That’s a specific risk. It’s worth asking whether the other products covered by the law share it.

Creatine works for strength. What do we know about its safety?

Before getting into whether creatine works, it helps to know what’s in the tub. Creatine is a compound your body makes naturally, mostly in the liver and kidneys, and stores primarily in your muscles. You also get it from foods like beef, pork, salmon, and herring. In your muscles, it helps replenish energy quickly during short, intense efforts, like sprinting or getting through another hard set. NIH sports supplement fact sheet.

Does taking extra creatine make a difference? For adults who lift, the evidence says it can. A 2024 meta-analysis found that adults under 50 who took creatine while resistance training gained more upper- and lower-body strength, on average, than those who trained and took a placebo. That benefit can occur without a rise in testosterone. Creatine and strength meta-analysis.

The practical downsides include water-weight gain and digestive upset. A 2025 review found a small rise in blood creatinine, a marker used to estimate kidney function, without a significant decline in kidney filtration over the periods studied. That’s reassuring for the people studied. It’s also a reason to tell your clinician you take creatine when they interpret your bloodwork. People with kidney disease should discuss supplementation with their clinician. Creatine and kidney function review.

Teens have been studied, too. In one small trial, competitive swimmers averaging about 15 years old improved on some sprint-swimming measures after nine days. A broader review of 13 studies involving 268 young participants found inconsistent performance results and identified no studies designed primarily to assess safety. A short sprint trial can tell us how swimmers performed that week. Parents deciding whether their teenager should take creatine regularly while growing have less evidence to work with. Adolescent swimmer trial and review of creatine in young athletes.

Protein powder can help an athlete eat enough

Think about the kid who eats lunch at 11, goes straight to practice after school, and gets home at 7. A shake can be a convenient way to get protein and calories into that day. If it adds calories the athlete wouldn’t otherwise eat, it can help with weight gain. How much of that gain is muscle depends in part on the training and what the athlete is already eating.

In adults who lift, a meta-analysis found that additional protein produced modest extra gains in muscle mass and strength. The average benefit for fat-free mass leveled off around 1.6 grams per kilogram of body weight per day from food and supplements combined. That’s an adult research finding. For a teenager, I’d start by looking at a normal school and practice day. Protein supplementation and resistance training meta-analysis.

A 10-week trial of 22 adolescent soccer players found that both the whey group and the group given an equal-calorie comparison product gained fat-free mass. The whey group didn’t gain more fat-free mass or strength. That leaves open what extra protein might do for a teen strength athlete who struggles to eat enough. Adolescent whey protein trial.

On safety, a review of adults without kidney disease found no meaningful difference in changes in kidney filtration between higher- and lower-protein diets over the periods studied. Milk-protein allergy and existing kidney disease can change the advice for an individual. The American Academy of Pediatrics says most young athletes who eat a balanced diet don’t need a protein supplement. Sometimes the athlete just needs something they’ll actually eat between school and practice. Higher-protein diets and kidney function review and American Academy of Pediatrics guidance.

Testosterone boosters are where the marketing gets ahead of the evidence

A bottle that says “supports testosterone” lets the buyer fill in the rest. More energy? More muscle? A higher number on a blood test? You’d need a different measurement to establish each one.

A systematic review looked at 52 studies covering 27 proposed testosterone boosters. Most ingredients failed to increase total testosterone. A few showed promise in particular groups, but that doesn’t show that a commercial blend will raise testosterone or build muscle in a healthy athlete. Correcting a nutrient deficiency is a different situation from taking extra vitamins or minerals when you already get enough. Systematic review of testosterone boosters and NovaGenix’s Do Testosterone Boosters Work?.

If a company wants me to believe its product will raise testosterone and help someone build muscle, I’d like to see a study on the actual product that measured both. A promising result for one ingredient tells me very little about a bottle with six others in it.

Did California go too far?

I think California has a reasonable goal. Teenagers are under real pressure about how they look, and concentrated stimulants and poorly characterized blends deserve scrutiny. Where I see potential overreach is using a muscle-building claim as a stand-in for the risk of the product itself.

I haven’t seen evidence in the research reviewed here of a pattern of serious harm from ordinary use of plain creatine or protein that would justify treating those products like high-caffeine blends. Long-term evidence in healthy teens is limited, especially for creatine. That’s a reason for parents and clinicians to use judgment. The studies also leave a policy question unanswered. Would restricting sales of these particular products reduce harm among teenagers?

If my teenager brought one of those tubs home, I’d ask what they wanted it to do, read the label with them, and look at the evidence for what’s actually inside. I’d want the law to make that same distinction.

Tim Bruce is a co-founder of NovaGenix Health & Wellness in Jupiter, Florida. He writes about patient education and how people make decisions about their health.