Can I say it?
Can I say “boost your immunity” in a supplement ad?
It depends. 5 rules fired across 3 sample sentences, and the checker's own text explains why.
The short answer
It depends. The bare phrase draws a warning, not a block. Add a few more words around it and the checker blocks it: 2 of 3 samples below hit a blocking rule. The first rule it hits is CG-EFF-010. Its reason: Immunity, regeneration and cellular-repair claims imply a physiological effect that needs scientific support, and they are common in disease-claim warning letters.
Source the rule cites: FTC Health Products Compliance Guidance; FTC Act section 5; 21 CFR 101.93
Checked as an ad promoting a supplement or wellness product.
A clear result is not an all-clear. The checker flags wording for review and does not know your evidence, your state or your platform's review. Read the limitations.
Sample wording, run through the checker
These are sentences written to contain the phrase, not real claims. Each ran through the real engine and the shipped rule-set when this site was built.
Boost your immunity naturally.
- WarningCG-EFF-010Efficacy and proof. Matched: “Boost your immunity”
Our IV drip will boost your immune system.
- BlockingCG-RFA-003Disease claims. Matched: “boost your immune”
- WarningCG-DIS-008Disease claims. Matched: “boost your immune system”
- WarningCG-RAF-010Efficacy and proof. Matched: “Our IV drip will boost your immune”
Boost your immunity all winter.
- Blocking
CG-TRA-003Disease claims. Matched: “Boost your immunity all winter” - WarningCG-EFF-010Efficacy and proof. Matched: “Boost your immunity”
What to say instead
This version came back with no rule fired:
Our vitamin blend is a daily supplement. Ask your doctor about your own needs.
What the rules themselves suggest:
- CG-RFA-003 Remove anticancer, anti-inflammatory and regenerative claims. Do not describe the product as acting on disease processes.
- CG-TRA-003 Remove prevention and protection claims. Do not say a product boosts immunity against a named illness or replaces a vaccine.
- CG-DIS-008 For supplements add the required disclaimer and notify FDA within 30 days of marketing; otherwise state plain facts such as "contains vitamin C".
The rules behind this answer
Reason, source and citation for each rule that fired, in the checker's own words. Blocking rules come first.
CG-RFA-003 · Blocks approval · Citation checked against stored text
Anti-cancer, anti-inflammatory, immune-restoring, detox or regenerative claims describe the treatment or mitigation of disease and are unapproved drug claims when made for a supplement, cosmetic or biologic.
Source: FDCA 201(g)(1); 21 CFR 101.93(g); FTC Health Products Compliance Guidance
Safer wording: Remove anticancer, anti-inflammatory and regenerative claims. Do not describe the product as acting on disease processes.
21 CFR 101.93(g) · Needs counsel review
CG-TRA-003 · Blocks approval
Claiming a supplement, IV drip or kit prevents COVID, flu or illness, or makes someone immune, is an unapproved prevention claim, and it can lead people to skip vaccination.
Source: FTC Act section 5; FTC COVID-19 health claim enforcement and warning letters; FDCA 201(g)
Safer wording: Remove prevention and protection claims. Do not say a product boosts immunity against a named illness or replaces a vaccine.
See source text · Needs counsel review
CG-DIS-008 · Warns · Citation checked against stored text
Immune claims are structure/function claims that need substantiation and, for supplements, the standard FDA disclaimer.
Source: FDCA 403(r)(6), 21 U.S.C. 343(r)(6); 21 CFR 101.93
Safer wording: For supplements add the required disclaimer and notify FDA within 30 days of marketing; otherwise state plain facts such as "contains vitamin C".
21 CFR 101.93, 21 U.S.C. 343 · Needs counsel review
CG-EFF-010 · Warns · Citation checked against stored text
Immunity, regeneration and cellular-repair claims imply a physiological effect that needs scientific support, and they are common in disease-claim warning letters.
Source: FTC Health Products Compliance Guidance; FTC Act section 5; 21 CFR 101.93
Safer wording: Describe the product's ingredients and what you can substantiate. Cite the study for any effect on immunity or tissue repair.
21 CFR 101.93 · Needs counsel review
CG-RAF-010 · Warns · Citation checked against stored text
Saying a product boosts or strengthens the immune system or protects against colds, flu or infection implies prevention of disease, which is not an allowed structure or function claim without evidence.
Source: FTC Act section 5 and FTC warning letters on immune and COVID-19 claims; 21 CFR 101.93(g). UK ASA rulings are the origin of the pattern but UK law is out of scope.
Safer wording: Use only supported structure and function wording such as supports immune health, add the standard disclaimer, and never imply disease prevention.
21 CFR 101.93(g) · Needs counsel review
Background: Structure/function claim in the glossary.
Questions
Which rule covers immunity claims?
Rule CG-EFF-010. It cites 21 CFR 101.93. The rule's reason: Immunity, regeneration and cellular-repair claims imply a physiological effect that needs scientific support, and they are common in disease-claim warning letters.
What should I write instead?
The rule's own suggestion for rule CG-EFF-010: Describe the product's ingredients and what you can substantiate. Cite the study for any effect on immunity or tissue repair.
If the checker shows nothing, can I publish?
No. A clean result means none of the checker's rules matched. It does not weigh your evidence, your state or your platform's review, and it is not legal advice. Read the limitations page for what it misses.
Next step
Check your own wording
Paste your copy into the free checker. Every flag names its rule and its source.