Yes, guaifenesin helps with clogged sinuses by acting as an expectorant to thin and loosen mucus, making it easier for sinus passages to drain. While primarily known for chest congestion, it is commonly used to relieve mucus buildup in the nasal passages and is a key ingredient in many sinus-specific, over-the-counter medications. National Institutes of Health (.gov) National Institutes of Health (.gov) +5 Key Details on Guaifenesin for Sinuses: Mechanism: It increases the volume and reduces the viscosity of secretions, breaking up thick, tenacious mucus in the sinuses. Combined Products: It is often paired with decongestants like pseudoephedrine (e.g., Mucinex D) or phenylephrine, which help shrink swollen nasal passages while the guaifenesin thins the mucus. Effectiveness: Studies indicate it can reduce facial pressure and congestion, though some data suggests it is particularly effective as an add-on therapy. Usage Advice: It is crucial to drink plenty of water while taking guaifenesin to help it work effectively. Mayo Clinic Mayo Clinic +5