Flonase (fluticasone propionate) is generally considered safe to continue or start using when you have COVID-19. No major medical society or regulatory body has issued guidance against intranasal corticosteroids during a coronavirus infection, and a growing body of research suggests they may even offer modest benefits for certain COVID symptoms, particularly the loss of smell. That said, there is one specific drug interaction worth knowing about if you’re prescribed Paxlovid, and the evidence on whether Flonase actually speeds recovery is more mixed than early headlines suggested.
Why People Wonder About Flonase and COVID
The question usually comes from one of two places. Either you already use Flonase for allergies or chronic sinusitis and you’ve caught COVID, or you’re dealing with COVID-related nasal congestion and wondering if Flonase could help. In either case, the concern is understandable: corticosteroids suppress parts of the immune system, and it seems reasonable to worry that dampening your nasal immune response during an active infection could make things worse.
But Flonase delivers a very small dose of steroid directly to the nasal lining, and very little of it enters the bloodstream. This is fundamentally different from systemic corticosteroids like prednisone or dexamethasone, which circulate throughout the body and carry real immunosuppressive risks at high doses. The localized nature of intranasal steroids is why allergists and ENT specialists have generally advised patients to keep using them during COVID.
What the Research Says About Smell Loss
Loss of smell was one of the signature symptoms of COVID-19, especially with earlier variants, and it remains the most studied reason for using Flonase during infection. A systematic review of randomized and quasi-experimental studies found that fluticasone and triamcinolone acetonide nasal sprays helped patients regain normal smell function roughly 23 days earlier than mometasone furoate nasal spray or oral corticosteroids. The same analysis found that nasal corticosteroid sprays ended smell loss about 47 days earlier than carbamazepine and outperformed several other interventions including omega-3 supplementation and olfactory training.1PLOS ONE. Effect of any form of steroids in comparison with that of other medications on the duration of olfactory dysfunction in patients with COVID-19: A systematic review of randomized trials and quasi-experimental studies A smaller study found that patients using fluticasone nasal spray showed statistically significant improvement in recognizing odors by day five compared to a control group, where smell either did not improve or worsened.2American Journal of Otolaryngology. The outcome of fluticasone nasal spray on anosmia and triamcinolone oral paste in dysgeusia in COVID-19 patients
However, a meta-analysis pooling six trials with over 700 patients painted a more cautious picture. It found no significant difference in the overall duration of smell loss between intranasal corticosteroid users and controls, and self-rated smell scores at two weeks and at the end of treatment did not significantly favor the steroid group. On the more encouraging side, objective smell testing did show higher scores in the steroid group by the end of treatment, and the proportion of patients who fully recovered from smell loss was higher among those using intranasal steroids, with about 1.7 times the odds of recovery.3PubMed Central. The Effect of Corticosteroids on Post-Covid-19 Smell Loss: A Meta-Analysis
The honest takeaway is that fluticasone probably helps some people recover their sense of smell faster, but it is not a guaranteed fix. The signal in the research is real but modest, and individual results vary. If you’ve lost your sense of smell from COVID, trying Flonase is a reasonable, low-risk option, but expecting a dramatic overnight turnaround would be setting yourself up for disappointment.
The Paxlovid Interaction You Should Know About
If you’ve been prescribed Paxlovid (nirmatrelvir/ritonavir) for COVID, the Flonase question gets more complicated. Ritonavir, one of the two active drugs in Paxlovid, is a potent inhibitor of the enzyme your body uses to break down many medications, including corticosteroids. This means that using Flonase while taking Paxlovid can cause fluticasone to build up in your system to much higher levels than a nasal spray would normally produce.
A real-world evidence analysis of the top 100 prescribed drugs in the U.S. identified corticosteroids, including fluticasone, among the medications expected to cause drug interactions with nirmatrelvir/ritonavir.4SpringerLink / AAPS J. Real-World Evidence of the Top 100 Prescribed Drugs in the USA and Their Potential for Drug Interactions with Nirmatrelvir; Ritonavir The concern is not theoretical: case reports have described patients developing symptoms of steroid excess, including a condition called Cushing syndrome, after taking ritonavir-containing regimens alongside inhaled or intranasal fluticasone. The symptoms can include unusual weight gain, elevated blood sugar, and suppression of your body’s own cortisol production.
In practice, a five-day course of Paxlovid alongside occasional Flonase use is unlikely to cause serious problems for most people. The risk rises the longer the two overlap and the higher the fluticasone dose. Still, this is worth mentioning to the doctor prescribing your Paxlovid. They may suggest switching to a different nasal spray like beclomethasone, which is less affected by ritonavir, or simply pausing the Flonase for the five days you’re on Paxlovid.
How Fluticasone Might Affect the Virus Itself
Beyond symptom relief, researchers have explored whether fluticasone changes anything about how SARS-CoV-2 behaves in the nose. The virus enters cells by latching onto a protein called ACE2 on the cell surface. Lab studies using human nasal tissue found that fluticasone propionate suppressed the expression of ACE2 when cells were stimulated with a viral mimic. The reduction was substantial at the RNA level, and a smaller but still statistically significant reduction appeared at the protein level.5PubMed Central. Fluticasone Propionate Suppresses Poly(I:C)-Induced ACE2 in Primary Human Nasal Epithelial Cells Separately, research involving patients with COPD found that those using inhaled corticosteroids had significantly reduced ACE2 expression in their airways compared to non-users, and that this effect appeared to work through suppression of the interferon signaling pathway the virus exploits.6Journal of Allergy and Clinical Immunology. COVID-19 Inhaled corticosteroids downregulate the SARS-CoV-2 receptor ACE2 in COPD through suppression of type I interferon
What does this mean in practical terms? Less ACE2 on nasal cells could theoretically make it harder for the virus to infect those cells, which sounds like a win. A large observational study using electronic health records did find that fluticasone use was associated with lower risk of COVID-19 outcomes.7PubMed Central. DrugWAS: Drug-wide Association Studies for COVID-19 Drug Repurposing And a retrospective cohort study found that among people using inhaled corticosteroids, those on fluticasone furoate had far fewer clinically detected COVID infections than those on budesonide.8BMJ Open Respiratory Research. Differential association of fluticasone furoate and budesonide with clinically detected COVID-19: a retrospective cohort study
But these are observational findings, and they come with serious caveats. People who use nasal steroids regularly tend to be allergy patients who may have different baseline health behaviors, viral exposures, or nasal physiology than non-users. The ACE2 reduction seen in lab dishes and airways does not automatically translate to fewer infections or milder illness. No randomized controlled trial has shown that starting Flonase prevents or meaningfully treats COVID infection. The lab findings are interesting and they explain why researchers kept pursuing this line of inquiry, but they should not be mistaken for proof that Flonase is a COVID treatment.
If You Already Use Flonase for Allergies
People with allergic rhinitis or chronic sinusitis who rely on Flonase as a daily medication face a particular dilemma when they test positive. The fear of “suppressing your immune system during an infection” can be strong enough that some people stop their nasal steroids cold turkey. This is generally a bad idea. Uncontrolled nasal inflammation, constant sneezing, and a swollen nasal lining on top of COVID congestion can make you significantly more miserable and may actually interfere with recovery by blocking sinus drainage.
The evidence does not support stopping intranasal corticosteroids during COVID. If anything, the retrospective data tilts slightly in favor of continued use. The study comparing inhaled corticosteroid users to non-users found that, under symptom-based testing, ICS users had fewer clinically detected COVID events, though the researchers cautioned this should be interpreted as exploratory due to baseline differences between groups.9BMJ Open Respiratory Research. Differential association of fluticasone furoate and budesonide with clinically detected COVID-19: a retrospective cohort study The bottom line for allergy patients: keep using your Flonase unless your doctor specifically tells you to stop.
Practical Tips for Using Flonase During COVID
If you decide to use Flonase while sick with COVID, a few practical points are worth keeping in mind. Nasal congestion from COVID can be severe enough that the spray does not penetrate well. Blowing your nose gently before spraying helps. Some people find that a saline rinse before Flonase clears enough mucus for the medication to reach the nasal lining where it works. A multidisciplinary review noted that saline nasal irrigation during COVID appears safe for most people, though it flagged the importance of using clean (distilled, boiled, or sterile) water rather than tap water, due to the rare but serious risk of waterborne infection.10PubMed Central. Saline nasal irrigation and gargling in COVID-19: a multidisciplinary review of effects on viral load, mucosal dynamics, and patient outcomes
Hygiene around the spray bottle itself matters more when you’re infected. The nozzle contacts your nostrils, which during COVID are loaded with virus. Wiping the nozzle with a clean tissue after each use and not sharing the bottle with household members are common-sense precautions. If you finish your COVID illness and still have half a bottle left, the spray inside remains sterile, but consider giving the nozzle tip a thorough cleaning.
Flonase does not work instantly. Its anti-inflammatory effects build over several days, so if you’re starting it fresh during COVID specifically for congestion or smell loss, give it at least three to five days before judging whether it’s helping. This is consistent with how it works for allergies: fluticasone is not a decongestant that clears your nose in minutes, but a steroid that gradually reduces the swelling causing the blockage.
Side Effects Worth Watching
Flonase is well tolerated by most people, but it is not side-effect free. An analysis of the FDA’s adverse event database found that intranasal corticosteroids as a class had the highest total number of reported adverse events among nasal sprays, with nosebleeds, headache, and difficulty breathing among the most common reports.11SAGE Journals (Annals of Otology, Rhinology & Laryngology). Adverse Events Associated with Intranasal Sprays: An Analysis of the Food and Drug Administration Database and Literature Review These numbers need context: corticosteroid nasal sprays are prescribed far more often than any other type, so the raw count of reports is naturally higher. The most common real-world side effect is nosebleed, usually mild and caused by the spray hitting the nasal septum. Aiming the nozzle slightly outward, toward the ear on the same side rather than straight up, reduces this risk.
During COVID specifically, keep in mind that COVID itself can cause headache, altered taste, and nasal discomfort, all of which overlap with Flonase’s known side effects. If you develop a new symptom after starting Flonase, it may be the spray, the virus, or both. Stopping the spray for a day or two to see if the symptom improves is a reasonable way to sort this out.
Flonase Versus Other Nasal Sprays for COVID Symptoms
Flonase is not the only option for nasal symptom relief during COVID. Oxymetazoline sprays like Afrin provide faster decongestion but should not be used for more than three consecutive days due to the risk of rebound congestion, where the nose becomes more blocked than it was before you started. Antihistamine nasal sprays like azelastine are another option, and azelastine was also identified in the same large drug-wide association study as being associated with lower risk of COVID outcomes.12PubMed Central. DrugWAS: Drug-wide Association Studies for COVID-19 Drug Repurposing For people who want both antihistamine and steroid action, a combination product (azelastine plus fluticasone, sold as Dymista) exists by prescription.
Plain saline sprays carry no drug interactions and no side effects beyond occasional mild stinging. They are the safest option if your goal is simply to keep your nasal passages moist and clear mucus, though they will not reduce the underlying inflammation the way a steroid spray does. For someone with mild COVID congestion and no history of nasal problems, saline alone may be sufficient. For someone dealing with persistent smell loss or severe congestion layered on top of chronic allergies, Flonase or a similar corticosteroid spray is likely the better choice.
When Smell Loss Lingers After COVID Clears
For some people, loss of smell outlasts the acute infection by weeks or months. This condition, sometimes lasting well beyond the point when the virus is detectable, is one of the more frustrating aspects of long COVID. The question then shifts from “can I use Flonase with COVID” to “should I use Flonase for lingering post-COVID smell loss.”
The systematic review that found fluticasone helped patients regain smell faster was examining use during or shortly after infection, not months later.13PLOS ONE. Effect of any form of steroids in comparison with that of other medications on the duration of olfactory dysfunction in patients with COVID-19: A systematic review of randomized trials and quasi-experimental studies The meta-analysis showing a higher proportion of smell recovery in the steroid group also focused on relatively near-term outcomes.14PubMed Central. The Effect of Corticosteroids on Post-Covid-19 Smell Loss: A Meta-Analysis For prolonged post-COVID anosmia lasting many months, the evidence for Flonase specifically thins out. ENT specialists often still recommend a trial of intranasal steroids in combination with olfactory training (the practice of deliberately sniffing specific scents daily to retrain the nerve pathways), but expectations should be calibrated. The damage to olfactory neurons in long-lasting cases may be structural rather than inflammatory, and a drug that works by reducing inflammation can only do so much when the problem is nerve regeneration.
If you’ve been using Flonase for post-COVID smell loss for several weeks without any improvement, it is worth having a conversation with an ENT specialist. They can conduct objective smell testing to establish a baseline, rule out other causes of smell loss, and discuss whether continuing the spray is likely to help or whether other approaches should take priority.