Based on NIH | Is it safe to take naproxen at night after eating tofu, or does soy interfere with its absorption or increase the risk of side effects?

Taking naproxen after a tofu or soy‑containing meal is generally considered acceptable, and soy foods are not known to meaningfully interfere with naproxen’s absorption or clearly increase its side‑effect risk. Food may slightly slow or lower the peak level of some NSAIDs (including naproxen), but the overall amount absorbed is usually similar, and taking naproxen with food can help protect the stomach. ^{[1] [2]}

What we know about naproxen and food

• Naproxen’s absorption can be modestly delayed by co‑administered agents like sucralfate, but the total amount absorbed (bioavailability) is not meaningfully changed. ^[1]
• Controlled studies show that eating a meal with controlled‑release naproxen slightly lowers the peak blood level (around 14%) without significantly changing the overall exposure over time, suggesting no substantial change in effectiveness. ^[2]
• Many product labels and clinical guidance allow or even encourage taking NSAIDs with food or milk to reduce stomach upset, reflecting the balance between comfort and consistent absorption. This aligns with the common recommendation to take naproxen with food if you have stomach sensitivity. ^[3]

What we know about soy and drug interactions

• Soy contains isoflavones that can affect certain drug‑metabolizing enzymes and transporters in laboratory and limited human studies, but the clinical significance is often unclear and tends to be drug‑specific. ^{[4] [5]}
• Documented interactions with soy are more relevant for drugs like some cancer therapies, thyroid hormone, or certain statins, and even then, findings are mixed and not always clinically important. There is no established, clinically significant interaction between dietary soy/tofu and naproxen. ^{[6] [7]}

Practical guidance for taking naproxen with soy

• If you tolerate naproxen, taking it at night after a tofu or soy‑based dinner is reasonable and can be gentler on the stomach. ^[3]
• Watch for the usual NSAID side effects such as indigestion, stomach pain, dark stools, heartburn, dizziness, or swelling, which can occur regardless of soy intake. Taking the lowest effective dose for the shortest necessary duration helps reduce risks. ^[8]
• If you use other medicines that increase bleeding risk (e.g., anticoagulants) or have a history of ulcers or kidney/heart issues, discuss NSAID use with your clinician. ^{[8] [9]}

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Quick comparison: food vs. soy effects

Factor	Food with naproxen	Soy foods (tofu, soy milk)
Peak level (Cmax)	May be modestly reduced; timing to peak may be delayed. [2] [1]	No specific evidence that dietary soy alters naproxen peak levels.
Overall absorption (AUC)	Generally unchanged or minimally affected. [2] [1]	No evidence of clinically meaningful change with naproxen.
GI comfort	Often improved when taken with food. [3]	Neutral; soy itself does not increase naproxen GI risk beyond general food effects.
Notable interactions	Sucralfate can slow rate but not extent of absorption. [1]	Lab and limited human data show enzyme/transporter effects; clinical relevance to naproxen is not established. [4] [5]

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Bottom line

Based on available evidence, eating tofu or other soy foods does not appear to meaningfully interfere with naproxen’s absorption or clearly increase side‑effect risk, and taking naproxen after a meal is a common strategy to reduce stomach upset. ^{[2] [1]} If you have risk factors for NSAID complications or take other interacting medications, consider a brief check‑in with your healthcare professional before regular use. ^{[8] [9]}