哈佛24週試驗：NR 使 NAD⁺ 水平提升三倍
長新冠如影隨形，讓全球數億人飽受腦霧、疲勞和失眠之苦。
In November 2025, a team from Harvard Medical School published a 24-week double-blind, placebo-controlled clinical trial in eClinicalMedicine, a journal in The Lancet family. The results showed that nicotinamide riboside (NR) increased NAD⁺ levels in the body by 2.6–3.1 times within five weeks. Exploratory analyses also suggested that after 10 weeks of continuous supplementation, participants experienced improvements in fatigue, sleep quality, depressive symptoms, and executive function.
SARS-CoV-2感染會活化PARP酶，這些酶會消耗大量NAD⁺。
NAD⁺減少會損害粒線體功能。
這會導致失控的發炎和認知疲勞。
NR是目前臨床支持度最高的NAD⁺前體之一，並已被證明能有效提升血液和組織中的NAD⁺水平。
研究設計
高劑量介入：每天2000毫克NR。
長期追蹤：24週，包括安慰劑期和NR期。
Key Finding 1: NR acts like a powerful “cellular charger”
The data were striking. After only 5 weeks of NR supplementation, participants’ blood NAD⁺ levels rose by 2.6–3.1 times. This demonstrates NR’s high bioavailability and its ability to rapidly replenish cellular energy capacity.
關鍵發現2：探索性分析中的正面訊號
儘管NR組與安慰劑組之間的嚴格統計比較未達顯著性（主要終點為陰性），但結合NR階段所有參與者（43人）的數據，與使用NR前的自身基線相比，顯示出幾個令人鼓舞的趨勢。
主觀認知報告（ECog）在安慰劑期和NR期均有改善。這表明，感知到的改善可能部分反映了期望效應或症狀隨時間的自然波動。
客觀認知測試（TMT-B，測量執行功能）顯示出不同的模式：反應速度僅在NR補充階段顯著改善。
Compared with subjective impressions, objective behavioral improvements are often considered stronger evidence of real physiological change. These findings therefore provide a noteworthy clue that NR may help alleviate long-COVID-related “brain fog.”
這項試驗提供了令人安心的證據：即使每天服用2000毫克，NR也表現出極佳的耐受性。
大多數不良事件輕微，主要是噁心或肌肉痙攣。
僅發生一例嚴重不良事件，且被判定與NR無關。
Together, these can form a synergistic “energy metabolism + neuroprotection” formulation matrix.
500–1000 mg/day is a commonly used supplemental range.
Continuous use for at least 10–12 weeks is recommended before evaluating subjective effects.
高劑量如2000毫克/天應在專業指導下使用。
This Lancet-affiliated study did not claim that “NR cures long COVID.” What it did show, through rigorous data, is that raising NAD⁺ levels and improving fatigue and sleep is a pathway worth exploring further.
NR是否能成為長新冠的真正突破，需要更大規模、更精確的臨床試驗來驗證。
對於尋求有臨床證據支持的NAD⁺前體的產品開發者而言，NR在證據和安全性方面仍是目前最強勁的選擇之一。
參考文獻：
Wu CY, et al. Effects of nicotinamide riboside on NAD+ levels, cognition, and symptom recovery in long-COVID: a randomized controlled trial. EClinicalMedicine. 2025;89:103633. doi: 10.1016/j.eclinm.2025.103633
In November 2025, a team from Harvard Medical School published a 24-week double-blind, placebo-controlled clinical trial in eClinicalMedicine, a journal in The Lancet family. The results showed that nicotinamide riboside (NR) increased NAD⁺ levels in the body by 2.6–3.1 times within five weeks. Exploratory analyses also suggested that after 10 weeks of continuous supplementation, participants experienced improvements in fatigue, sleep quality, depressive symptoms, and executive function.
第一部分
Why NR? — NAD⁺ as the “Master Switch” of Cellular Energy and Immunity
長新冠患者常表現出NAD⁺耗竭：SARS-CoV-2感染會活化PARP酶，這些酶會消耗大量NAD⁺。
NAD⁺減少會損害粒線體功能。
這會導致失控的發炎和認知疲勞。
NR是目前臨床支持度最高的NAD⁺前體之一，並已被證明能有效提升血液和組織中的NAD⁺水平。
第二部分
試驗：24週內發生了什麼？
這是一項嚴謹設計的研究，涉及58名患有腦霧的長新冠患者。研究設計
高劑量介入：每天2000毫克NR。
長期追蹤：24週，包括安慰劑期和NR期。
Key Finding 1: NR acts like a powerful “cellular charger”
The data were striking. After only 5 weeks of NR supplementation, participants’ blood NAD⁺ levels rose by 2.6–3.1 times. This demonstrates NR’s high bioavailability and its ability to rapidly replenish cellular energy capacity.
關鍵發現2：探索性分析中的正面訊號
儘管NR組與安慰劑組之間的嚴格統計比較未達顯著性（主要終點為陰性），但結合NR階段所有參與者（43人）的數據，與使用NR前的自身基線相比，顯示出幾個令人鼓舞的趨勢。
主觀與客觀認知變化
出現了一個有趣的細微差別：主觀認知報告（ECog）在安慰劑期和NR期均有改善。這表明，感知到的改善可能部分反映了期望效應或症狀隨時間的自然波動。
客觀認知測試（TMT-B，測量執行功能）顯示出不同的模式：反應速度僅在NR補充階段顯著改善。
Compared with subjective impressions, objective behavioral improvements are often considered stronger evidence of real physiological change. These findings therefore provide a noteworthy clue that NR may help alleviate long-COVID-related “brain fog.”
NAD⁺與睡眠改善
The study also found that the magnitude of NAD⁺ increase was significantly associated with improvements in sleep quality (p = 0.03), offering preliminary support for a possible “NAD⁺ mechanism → symptom improvement” pathway.
第三部分
安全性：即使在高劑量下也具有良好的耐受性
許多消費者擔心高劑量補充的安全性。這項試驗提供了令人安心的證據：即使每天服用2000毫克，NR也表現出極佳的耐受性。
大多數不良事件輕微，主要是噁心或肌肉痙攣。
僅發生一例嚴重不良事件，且被判定與NR無關。
結論
NR在長期、高劑量使用下表現出良好的安全性和耐受性，支持其作為功能性食品或膳食補充劑成分的潛在應用。對產品開發者和消費者的實際啟示
潛在應用領域
新冠後症候群支持、慢性疲勞、睡眠障礙。建議的搭配成分
NR可能與以下成分產生協同作用：PQQ（粒線體生物合成）、輔酶Q10（支持電子傳遞鏈）、NMN（另一種NAD⁺前體）、鎂（支持神經系統鎮靜）。Together, these can form a synergistic “energy metabolism + neuroprotection” formulation matrix.
劑量和時間參考
根據這項研究和先前的文獻：500–1000 mg/day is a commonly used supplemental range.
Continuous use for at least 10–12 weeks is recommended before evaluating subjective effects.
高劑量如2000毫克/天應在專業指導下使用。
第四部分
最終思考：科學中微小但有意義的一步
Scientific progress is rarely instantaneous, and science is never perfect — but each study helps refine the direction forward.This Lancet-affiliated study did not claim that “NR cures long COVID.” What it did show, through rigorous data, is that raising NAD⁺ levels and improving fatigue and sleep is a pathway worth exploring further.
NR是否能成為長新冠的真正突破，需要更大規模、更精確的臨床試驗來驗證。
對於尋求有臨床證據支持的NAD⁺前體的產品開發者而言，NR在證據和安全性方面仍是目前最強勁的選擇之一。
參考文獻：
Wu CY, et al. Effects of nicotinamide riboside on NAD+ levels, cognition, and symptom recovery in long-COVID: a randomized controlled trial. EClinicalMedicine. 2025;89:103633. doi: 10.1016/j.eclinm.2025.103633
