Margaret Thatcher was apparently fond of alternative health cures and was sent them by prolific romance author Barbara Cartland, newly released documents show.

Thatcher, who famously slept for only four hours a night, received “nutrimental capsules” from the novelist “in case you ever feel tired”.

On a separate occasion Thatcher was sent a further supplement, possibly to address jetlag or travel sickness ahead of a trip to the Far East.

Cartland, who corresponded with Thatcher fairly regularly and lunched with her, sent a package dated 8 June 1989.

“My dear prime minister, you were wonderful last night, as usual,” she wrote.

Margaret Thatcher's Belgravia home yours for £30m Show all 6 1 /6 Margaret Thatcher's Belgravia home yours for £30m Margaret Thatcher's Belgravia home yours for £30m The dining room The layout and design of the formal dining room and interlinking study on the ground floor has been reinstated exactly as Baroness Thatcher had it during her 22 years at the property, providing an impressive link to the property’s historical significance. Savills Margaret Thatcher's Belgravia home yours for £30m The '73' plaque Several features from Baroness Thatcher’s time at the property remain, beginning at its entrance; the inlaid ‘73’ plaque in the doorstep was installed by her in 1991 Savills Margaret Thatcher's Belgravia home yours for £30m The study "If only the walls could talk, one could almost imagine Ronald Reagan and other heads of state sitting with Baroness Thatcher in her dining room,” Richard Gutteridge, Head of Savills Sloane Street office said. Savills Margaret Thatcher's Belgravia home yours for £30m Hallway Leconfield chose Hopton stone flooring for the entrance hall, the same used in the Houses of Parliament. The front door is steel-lined ensuring it is bombproof. Savills Margaret Thatcher's Belgravia home yours for £30m Exterior Chester Square is one of London’s most prestigious and desirable addresses. Plaques on the other side of the square commemorate Matthew Arnold, the poet, and Mary Shelley, the author of Frankenstein Savills Margaret Thatcher's Belgravia home yours for £30m The drawing room The entire first floor of the property is dedicated to the drawing room and library, with views of Chester Square and 3.5 metre ceiling heights. It was often said to be Baroness Thatcher’s favourite room of the house. The relaxed yet luxurious space now also features a pair of original Louis XVI fireplaces and parquet flooring, selected to match the house’s original floor. Savills

“It is incredible, with all you do, how you can still look as though you were 25.

“In case you ever feel tired, I am enclosing the very latest product we have in the health movement, which takes oxygen to every part of the body, including the brain.

“My son, aged 51, says that he wakes up in the morning and feels like a boy of 16, and at nearly 88 I find it fantastic.”

In a letter dated 15 June 1989, Thatcher thanked Cartland for the “charming letter” and the “nutrimental capsules”.

Cartland then wrote to Thatcher’s diary secretary Amanda Ponsonby on 3 July 1989 with further supplements ahead of the prime minister’s planned trip to the Far East.

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“Thank you so much for being most kind and saying that you will give the enclosed to the prime minister,” wrote Cartland.

“I hope that there are enough because it is a very long trip.

“I did it myself and it does feel ghastly when you get home.

“Do impress on her that as far as I know there are no side-effects at all, and they are not soporific, so that you feel you must go to sleep.

“It just stops that awful feeling in the head and ears...”

Millionaire industrialist Emmanuel Kaye, once a strong supporter of the Conservative Party, wrote to Thatcher that year after seeing her at the opera at Glyndebourne and offered advice about her supplements.

He said he could “sort out vitamins, minerals etc and, if you like ... check whether the vitamin C and the royal jelly you are having are of the best variety for you and work out the optimum dosage”.

Kaye also mentioned he had evolved “an advanced form of homeopathy called body tuning”, though it is not known whether he did any for Thatcher.

The same year, a profile entitled The Blooming of Margaret Thatcher appeared in Vanity Fair, claiming that Thatcher was fond of “electric baths” – in which 0.3 amps of electricity was run through water – in a bid to stay youthful.

Chris Collins, of the Margaret Thatcher Foundation, said: “The impression of dottiness, of a woman ‘slightly off her trolley’, was not one that [Thatcher’s press secretary Bernard] Ingham could treat lightly and the ‘electric baths piece’ attracted a lot of attention one way or another in the world’s press.”

He said that references to health cures in Thatcher’s correspondence were “obscure, perhaps deliberately so”, adding that he believed her interest was genuine.

The Margaret Thatcher Foundation is gradually overseeing the release of her private files through the Churchill Archives Centre in Cambridge.

Members of the public will be able to browse the archive from Monday by visiting http://www.margaretthatcher.org