This section collects things that look cheap and effective. Once the original studies are opened, their benefit is close to zero, equal to zero, or in some cases negative. The items are grouped by subject below. Item numbers are in parentheses. Supplements: multivitamins (item 1), ordinary fish oil (item 2), vitamin D supplements (item 3), antioxidant supplements to prevent cancer (item 4), chondroitin for knee osteoarthritis (item 5), vitamin C to prevent colds (item 6), spending a lot on health products (item 10), taking probiotics long term (item 11), buying detox and colon-cleansing products (item 13), loading calcium after a fracture (item 30), relying on melatonin to cure long-term insomnia (item 34). Check-ups and small findings: a whole-body PET-CT and a tumour-marker panel (item 7), a general check-up package (item 18), do not take medicine for high uric acid if it has never hurt (item 19), do not have a gallbladder stone removed if it has never hurt (item 20), do not give up calcium to prevent kidney stones (item 21), do not have arthroscopic clean-out for degenerative knee pain (item 33). Health sayings: counting on a wristband to help you lose weight (item 8), buying organic food (item 9), cold showers to strengthen immunity (item 12), not forcing yourself to drink water (item 14), blue-light glasses (item 16), treating blood donation as health care (item 17), breakfast or intermittent fasting to control weight (item 26), counting on a correct lifting posture to prevent low-back pain (item 29), demanding an IV drip for a cold or fever (item 35). Spending money on luck and on mood: paying for fortune-telling and horoscopes (item 15), buying crystals, pixiu, and similar objects (item 22), buying things to improve your mood (item 23), spending more in order to move up a tier (item 24), not saving because you think people can die at any time (item 32). Willpower and sex: willpower is like a muscle (item 25), masturbation harms the body (item 27), conversion of sexual orientation (item 28). Answers from AI: judging your own illness with an AI chatbot (item 31).
English, Russian and Spanish use dlgrv’s unofficial translations. Newly revised entries appear in the Chinese original until a checked translation is available. The author’s latest Chinese text is authoritative. Translation revision: dlgrv/HowToLiveBetter · b25fa8a
Over 14000 male doctors took multivitamins for eleven years. The number of serious heart and vascular problems, as well as deaths, was virtually identical between those who took them and those who didn’t. When nine separate trials involving more than 50000 participants were pooled together, there was no measurable effect on mortality at all. Skipping them saves you between 200 and 700 yuan each year. This does not apply to people who have been medically diagnosed with specific nutrient deficiencies, nor to pregnant women needing folic acid.
Cost
They cost roughly 0.5 to 2 yuan per day, or 200 to 700 yua…
Benefit
The PHS II trial enrolled 14641 male doctors and followed them for a median period of 11.2 years (some longer,…
Two large trials enrolled 26000 and 15000 people with diabetes respectively. For those who took 1 gram of fish oil daily, the rates of major cardiovascular events and death were identical to those who did not take it. The fact that eating fish is beneficial does not mean fish oil capsules are equally helpful. Skipping them saves you 400 to 1000 yuan each year.
Cost
It costs roughly 1 to 3 yuan per day, or 400 to 1000 yuan…
Benefit
The VITAL trial included 25871 participants who took 1 gram of fish oil daily for a median follow-up of 5.3 ye…
People who were not deficient and then supplemented for 5 years had the same numbers of cancers, cardiovascular disease, and deaths as those who did not. Adults who rarely go out and get little sun may take 400 IU a day and should not exceed 2000 IU a day. At high doses, bone density falls more and falls increase. Fatigue alone does not mean vitamin D deficiency; if you have been tired for weeks with no clear reason, see a doctor.
Cost
Roughly 0.2 to 0.5 yuan per day, or 100 to 200 yuan per ye…
Benefit
The VITAL trial enrolled 25871 people and tested 2000 IU daily against placebo, with a median follow-up of 5.3…
Antioxidant supplements are not merely useless. Pooling 78 trials and nearly 300000 people, in the more rigorously designed trials those who took them had a slightly higher death rate. In two large trials done specifically on smokers, beta-carotene raised the share who got lung cancer by 18% to 28%. Deaths were also higher by 8% to 17%. Smokers and people exposed to asbestos especially should not take them.
Cost
Roughly 0.5 to 2 yuan per day. For smokers, the real cost…
Benefit
Cochrane analyzed 78 randomized controlled trials with 296707 participants. Overall, those taking antioxidant…
People with knee osteoarthritis who took a placebo for 24 weeks also had about six in ten say the pain eased. Those on glucosamine or chondroitin were only four or five percentage points above that — small enough that it may be chance. Spending 700 to 1800 a year buys an effect that is basically the same as placebo.
Cost
Roughly 2–5 RMB per day, or 700–1800 RMB per year.
Benefit
The GAIT trial enrolled 1,583 people with knee osteoarthritis and followed treatment for 24 weeks. Even in the…
Taking vitamin C every day will basically not make you catch fewer colds, and starting only after you already have a cold works only sometimes. Daily use can shorten one cold by about 8%; whether 300 to 500 a year is worth it is your call. Marathon runners and soldiers marching in cold regions are the exception: among them, those who take it get about half as many colds.
Cost
Each effervescent tablet costs roughly 1–2 yuan;
Benefit
Cochrane’s pooled analysis of 29 trials with 11306 participants indicates that regular vitamin C consumption d…
When people without symptoms get screened, what turns up most often is a false alarm. Over eight in ten who get a whole-body CT have at least one “abnormality” noted, and nearly four in ten are called back for more tests, yet most findings are benign. Women screened with ovarian-cancer markers do not die less of ovarian cancer, and some have had surgery for nothing after a false alarm.
Cost
A whole-body PET-CT costs roughly 7000–10000 yuan per scan…
Benefit
The USPSTF, which evaluates preventive measures in the U.S., assigned a D rating to CA-125 testing and ultraso…
Overweight people on the same diet and exercise plan lost 3.5 kg in two years if they wore a fitness band, while those without one lost 5.9 kg. To lose weight, the device is not money you have to spend.
Cost
Devices cost between 200 and 2000 RMB. Plus, you have to c…
Benefit
The IDEA trial involved 471 overweight or obese adults and lasted 24 months. All participants followed identic…
There is no strong evidence that organic food is more nutritious. Only 3 studies looked at how healthy people were after eating it, and none found a difference. Organic produce does have pesticide residues detected 30 percentage points less often, but a detection is not the same as exceeding the limit.
Cost
Typically 1 to 3 times the price of regular versions of th…
Benefit
One systematic review brought together 17 human studies and 223 studies on food composition. Its conclusion: “…
Multivitamins, fish oil, vitamin D, and other common ingredients have already been checked one by one in the first six items of this section; none showed a benefit. The line on the pack — “Health food is not a drug and cannot replace drug treatment of disease” — is required by the agency that regulates health foods. If the money is meant as a gift for parents brought to the door, the intention is fine; only the product is the wrong choice.
Cost
Prices range from a few hundred to tens of thousands of yu…
Benefit
What you get back is the money saved. The reasons are in the first 6 items of this section. The most common in…
Pooling 45 trials in healthy adults, taking probiotics does not lastingly change the gut bacteria; stop and they go back. Blood lipids also do not improve. Antibiotic-related diarrhea and similar specific cases have other evidence; they are not in this item.
Cost
Roughly 2–5 RMB per day, or 700–1800 RMB per year.
Benefit
This review concludes that there’s no solid proof that probiotics can produce lasting alterations in gut micro…
In a trial of 3018 people, those who took cold showers had 29% fewer sick-leave occasions. But the total days of leave matched everyone else, so it does not mean less illness. A 2025 pooling of 11 trials found that after cold water, markers of inflammation rose briefly and immune markers did not change. Wash if you like; just do not treat it as a health investment.
Cost
No cost at all. It requires enduring discomfort for 30 to…
Benefit
A randomized controlled trial conducted in the Netherlands enrolled 3018 participants. After a hot shower, the…
One review examined whether there is any evidence supporting detox diets. It concluded that while the detox industry is huge, there is very little clinical evidence to back it up, and no randomized controlled trials have ever been conducted on commercial detox diets. As for the claim that an “acidic body pH causes cancer,” a search of 8278 research papers yielded just one study that met the criteria — and even that showed no link.
Cost
Several hundred to several thousand yuan. Fasting as a way…
Benefit
That same review reiterated that despite the rapid growth of the detox market, there is almost no clinical evi…
Someone chased down the source of “8 glasses a day” and found not a single study that supports it. Food and other drinks already carry a lot of water, so you need not drink that much. This conclusion applies only to healthy adults who live in a mild climate and are not very active. Hot outdoor work, hard exercise, and people who must drink more for treatment or prevention should drink more on purpose.
Cost
No cost at all. It does require some time and effort to re…
Benefit
One literature review specifically checked the “8×8” claim — 8 glasses a day, 8 ounces each. Its conclusion wa…
There is a classic classroom experiment: students are given 'personality analyses' that are actually identical for everyone, yet most people find them remarkably accurate. This is precisely why fortune-telling seems accurate. An astrologer's success rate in picking correctly is about the same as random guessing. The cost is more than just a few dozen yuan: a fortune-telling gang in Xixian, Henan, collected 'incense money' and 'offering packages' of up to 3888 yuan, and the ringleader was sentenced to eleven years in prison.
Cost
It costs nothing. The hard part is giving up a quick short…
Benefit
Classic classroom experiment: after a personality test, students got a “personal analysis” that was identical…
Blue-light lenses show no benefit; skipping them saves a few hundred to over 1000 yuan in mark-up. Compared with ordinary lenses, studies found no clear difference in eye fatigue or visual clarity, and no evidence was found that they protect the retina. Screen-related ache and dryness can ease; they do not permanently ruin the eyes. What does ruin eyes is welding arc light and lasers.
Cost
These glasses cost nothing, and you’ll also avoid paying t…
Benefit
A 2023 Cochrane systematic review included 17 randomized controlled trials, each with 5 to 156 people, followe…
Claims that donating blood prevents heart attacks or reduces deaths are unreliable. Those conclusions stem from observational data, and people who regularly donate are generally healthier to begin with. When this baseline difference is accounted for, the original claim that “each additional yearly donation lowers mortality by 18.6%” drops to just 7.5%. One actual randomized trial found no difference in death rates between donors and non-donors. On the other hand, donating too often does make people feel weak and cold — precisely because of iron loss.
Cost
There is no monetary cost. A single donation — including r…
Benefit
The Kuopio study in Finland followed 2862 men aged 42–60 for nearly nine years. In the 24 months prior to trac…
People who regularly undergo generic health checks have the same mortality rates as those who don’t, including deaths from cardiovascular disease and cancer. It’s enough to get the evidence‑based screenings that match your age and gender. Individuals over 35 can have their blood pressure measured for free once a year, and those 65 or older receive a free annual health check.
Cost
There’s no cost at all;
Benefit
The 2019 update of a Cochrane systematic review included 17 randomized controlled trials. For overall mortalit…
For people whose uric acid is over the limit but who have never had a gout attack or tophi, the American College of Rheumatology conditionally recommends not starting uric-acid–lowering drugs yet. Treat 24 people for 3 full years and you prevent only one gout attack. Hoping it protects the kidneys also fails: kidney patients on the drug still lose kidney function as fast as those on placebo. Treat only after a real attack.
Cost
There’s no cost at all;
Benefit
The 2020 gout guidelines from the American College of Rheumatology address asymptomatic hyperuricemia, defined…
For people with gallstones but no pain, roughly 80% remained symptom-free over the next nine years. Without any intervention, only about 0.1% to 0.3% develop acute cholecystitis or pancreatitis each year. Gallbladder removal isn’t risk-free either: roughly 1.5% of patients suffer bile duct injury. That’s why European and UK medical guidelines recommend against surgery when there are no symptoms.
Cost
There’s no cost at all — you even avoid the expense of gen…
Benefit
Italy’s MICOL population survey ultrasound-scanned 11229 people aged 29 to 69. It found 856 with gallstones, o…
People who’ve had calcium oxalate stones are often advised to limit calcium intake, but randomized trials show the opposite. A study with 120 men who repeatedly developed stones and had elevated urinary calcium divided them into two groups: one ate a normal amount of calcium while cutting back on animal protein and salt; the other followed a traditional low‑calcium diet. After five years, recurrence rates were 12 out of 60 versus 23 out of 60 — meaning the normal‑calcium group had half the risk. UK guidelines also advise against restricting calcium.
Cost
No cost at all. In fact, it’s easier — no need to constant…
Benefit
This five‑year randomized trial enrolled 120 men with recurrent calcium oxalate stones and high urinary calciu…
There is absolutely no verifiable evidence supporting claims that wearing such items can change one’s fate, attract wealth, or improve health. These assertions work on the same principle as fortune-telling: they are phrased so vaguely that people naturally interpret them as applying to themselves. In 2026, a livestream seller was investigated for false advertising after fabricating the materials used in its products and falsely claiming that they could prevent or treat rheumatism. Buying them as decorative accessories is fine.
Cost
There is no monetary cost involved. The only requirement i…
Benefit
Classic classroom experiments demonstrate that when participants receive the same generic “personality analysi…
People who put more weight on money and things feel less happy themselves, but the link is weak and you cannot tell which causes which. Other research finds that spending on an experience makes people happier than buying stuff. So for the same spend, putting it toward going out once is more likely to make you happier than filling a shopping cart.
Cost
No cost at all. The hard part is resisting the urge to buy…
Benefit
This meta-analysis combined data from 259 independent studies, covering a total of 753 effect sizes. The resul…
Holding income equal, the more neighbours earn, the lower this person’s reported happiness. It mainly shows up with neighbours of the same education level, and more clearly in people who often deal with neighbours. So money spent to move into a place where everyone is better off than you buys moving yourself down a tier. But when incomes rise together, people still feel better off.
Cost
No cost at all. All you need to do is ask one extra questi…
Benefit
The National Survey of Family and Households (NSFH) in the U.S. surveyed the same individuals twice. Researche…
The popular idea is that after doing something that requires self‑control, it becomes easier to give in to temptation later on, so we should “save” our willpower. Yet 23 laboratories and 2,141 participants repeated this experiment using the same protocol, and the results were essentially null. Stop using “I’ve run out of willpower today” as an excuse, and don’t spend money on courses that promise to help you conserve it.
Cost
No cost at all. All that needs changing is the way we talk…
Benefit
A multi-lab preregistered replication had 23 laboratories and 2141 participants. They redid the sequential-tas…
The popular claim is that skipping breakfast makes people binge at lunch and dinner so the day’s total is higher. Short trials lasting a few weeks did not find that: people who skipped breakfast ate a bit over 200 kcal less in a day and weighed a little less. 16:8 versus simply eating less: body weight after a year also did not differ. People who skip breakfast long term have more cardiovascular disease, but that is only an association; all-cause death shows no difference.
Cost
There’s no monetary cost. What you save is the mental ener…
Benefit
Let’s first address the claim that skipping breakfast causes people to eat more later in the day. One meta-ana…
No evidence that masturbation harms the body was found. Men who ejaculate more have about 20% less prostate cancer, though some research also saw higher risk in those who did it often when young. A few people feel weak and flu-like after every ejaculation for days — a rare disease; see urology or andrology. Feeling “addicted to porn” more often comes from the clash with one’s own morals.
Cost
No cost. What you save is the money spent on "kidney-tonif…
Benefit
First the body. A U.S. study followed 31925 men through 2010. Each reported how many ejaculations a month, the…
After reviewing the evidence, an American Psychological Association expert panel said these conversion efforts are unlikely to change sexual orientation and may cause harm. In a U.S. survey, people who had undergone conversion reported suicidal thoughts over their lifetime more often. In China, a psychiatric hospital forcibly admitted a man under “sexual preference disorder”; the court found an infringement and ordered 5000 yuan in compensation.
Cost
No cost. What is saved is the revenue of conversion agenci…
Benefit
The American Psychological Association’s 2009 task-force report says efforts to change sexual orientation are…
Workers who received lifting training did not subsequently have less back pain than those who did not. People who bent their backs more while lifting were not found to develop back pain more often. Heavier and more frequent lifting were associated with back pain: the heavier each load and the more lifts per day, the more common back pain was. This is only an association, and some studies found none. Regular exercise reduced back-pain episodes by more than 30% to more than 40%.
Cost
No expense. You do not need to obsess over whether your ba…
Benefit
First training. The 2011 Cochrane systematic review pooled 9 randomized trials and 20101 employees. In 7 trial…
None of the randomized trials of vitamin D supplementation after a fracture found better bone healing. Studies combining calcium and vitamin D are scarce, so their benefit is uncertain. A large bowl of bone broth contains only a small fraction of the calcium you need each day. People with an existing vitamin D deficiency or osteoporosis are a separate case.
Cost
It costs nothing and saves the money and effort spent on c…
Benefit
First vitamin D. A 2023 systematic review included 14 studies and 2734 fracture patients. The authors conclude…
Hand a complete case to an AI and it names the right condition nine times out of ten or more. But ordinary people who ask it about symptoms identify the condition less often than people who just searched online, and are no better at judging whether to go to the emergency room. On legal questions, general-purpose AI makes things up in at least 58% of its answers, and will go along with a wrong premise in your question.
Cost
Free. Each check costs a few minutes to half an hour. Ask…
Benefit
First medicine. A 2026 Nature Medicine randomized trial enrolled 1298 ordinary people in the UK;
By WHO figures for China, about 92% of people aged 30 live to 60, and over half live to 80. Young people commonly overestimate how likely they are to die early; living by that feeling, they save about a quarter less than they should. From the numbers above, most people need to save for living into old age.
Cost
No money needed. When the thought “I could be gone any day…
Benefit
First, consider how long people can live. The World Health Organization’s Global Health Observatory produced a…
For middle-aged and older people with degenerative knee pain, arthroscopic clean-out or cutting a piece of meniscus is no better than sham surgery. Sham surgery only cuts a few skin holes; afterward pain and walking match real surgery. Any benefit lasts a few months at most and may invite leg clots. Sticking with leg training eases knee pain; overweight people who also lose weight hurt even less.
Cost
No surgery fee, and you also save 2 to 6 weeks of recovery…
Benefit
First osteoarthritis. A 2002 trial split 180 people with knee osteoarthritis into three groups: arthroscopic c…
People who sleep poorly and take melatonin fall asleep about 7 minutes sooner on average than on placebo, and sleep about 8 minutes more. The American Academy of Sleep Medicine does not recommend it for chronic insomnia. In China it is sold as a health food; the label says “this product cannot replace drugs.” Crossing 5 or more time zones by air for jet lag, it can ease jet-lag symptoms.
Cost
No money, and you also save long-term melatonin purchases.…
Benefit
First how large the effect is. A 2013 meta-analysis pooled 19 trials and 1683 people. Each trial was randomize…
Ordinary colds and viral sore throat are listed by Guangdong health authorities as conditions that in principle do not need an IV. At a National Health Commission briefing an expert clarified that seasonal drips do not wash plaque out of vessels and may add load on heart and kidneys. Of drug adverse reactions reported nationwide, over half involve injection routes, and nine in ten of those are intravenous.
Cost
No money, and you also save the drip fee and hours sitting…
Benefit
No study specifically compared IV versus no IV for a cold, so this item rests on official documents and monito…
